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5-18

Model 2790 SourceMeter 

®

Switch System Reference Manual

Ratio and channel average (7702 only)

klqb

Ratio or channel average can only be performed with a 7702 module installed. 
You can skip this topic if not using a 7702 module in your test system. 

With a 7702 switching module installed in the Model 2790, the ratio or average of two 
channels can be calculated and displayed. The ratio calculation can be done on the DCV 
function and the channel average calculation can be done on the DCV function.

Ratio and channel average are calculated as follows:

where:  Chan A is the selected (closed) channel.

Chan B is the paired channel for the installed switching module.
Ratio and Channel Average is the displayed result of the respective calculation.

Paired channels are used for ratio and channel average. For example, the Model 7702 
switching module has 40 channels that can use ratio and channel average. The primary 
channels (1 through 20) are linked to the paired channels (21 through 40). Channel 1 is 
paired to channel 21, channel 2 is paired to channel 22, and so on.

When ratio or channel average is enabled, the Model 2790 measures the closed primary 
channel. It then opens the primary channel and closes and measures the paired channel. 
Ratio or channel average is then calculated from the two readings and displayed. If the 
Model 2790 is configured for continuous measurements, the two-channel scan will con-
tinue to repeat and refresh the display with each new calculated reading.

The ratio or channel average calculation can only be enabled if a valid switching channel 
is closed. If no channel is closed when you attempt to enable one of these calculations, the 
“CLOSE A CHAN” message will be displayed to remind you to first close a valid chan-
nel.

A primary channel must be closed before you can enable ratio or channel average. If 
a paired channel is instead closed, message “INVALID CHAN” will be displayed to 
indicate the settings conflict.

klqb

The various instrument operations, including Ratio or Channel Average, are 
performed on the input signal in a sequential manner. See 

Appendix C

 for 

details. It includes a flowchart showing where in the processing sequence that 
Ratio or Ch Avg operation is performed. 

Ratio

Chan A
Chan B

------------------

=

Channel Average

Chan A

Chan B

+

2

-------------------------------------------

=

Содержание 2790

Страница 1: ...m o c y e l h t i e k w w w E C N E D I F N O C F O E R U S A E M R E T A E R G A Reference Manual 2790 901 01 Rev E August 2011 Model 2790 SourceMeter Switch System...

Страница 2: ...Model 2790 SourceMeter Switch System Reference Manual 2011 Keithley Instruments Inc All rights reserved Cleveland Ohio U S A Document Number 2790 901 01 Rev E...

Страница 3: ......

Страница 4: ...form them Otherwise they should be performed only by service personnel Service personnel are trained to work on live circuits perform safe installations and repair products Only properly trained servi...

Страница 5: ...standing on a dry insulated surface capable of withstanding the voltage being measured The instrument and accessories must be used in accordance with its specifications and operating instructions or t...

Страница 6: ...ting and type are the same Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component note that selected parts should b...

Страница 7: ......

Страница 8: ...oltage and replacing fuse 1 14 Power up sequence 1 15 Keyclick 1 16 Display 1 16 Status and error messages 1 16 Remote programming display 1 16 Defaults and user setups 1 18 Saving and restoring setup...

Страница 9: ...itching module capabilities 2 31 Model 7702 switching module 2 33 Switching module capabilities 2 33 Schematic diagram 2 34 Memory patterns 2 36 Description 2 36 Recalling memory patterns from the fro...

Страница 10: ...ents 3 27 Trigger level 3 27 Gate time 3 27 Connections 3 28 Frequency and period measurement procedure 3 29 Continuity testing 3 30 Connections 3 30 Continuity testing procedure 3 31 Remote programmi...

Страница 11: ...xIohms 5 12 SxVohms 5 13 Basic operation 5 14 Remote programming math 5 15 Ratio and channel average 7702 only 5 18 Basic operation 5 19 Remote programming ratio and channel average 5 21 dB 5 22 Remot...

Страница 12: ...anning programming example 7 33 Scanning examples 7 33 External trigger scan 7 34 Monitor scan 7 37 8 Triggering Trigger model 8 2 Idle 8 2 Control source and event detection 8 3 Delay auto or manual...

Страница 13: ...ents 10 2 Pseudocards 10 2 Autozero 10 2 dB calculation 10 2 Separate function setups 10 2 DCV input divider 10 3 Multiple channel operation 10 3 GPIB setup 10 3 GPIB standards 10 3 Selecting GPIB and...

Страница 14: ...r sets 11 2 Queues 11 2 Clearing registers and queues 11 4 Programming and reading registers 11 5 Programming enable registers 11 5 Reading registers 11 6 Status byte and service request SRQ 11 6 Stat...

Страница 15: ...l conditions 16 2 Warm up period 16 3 Line power 16 3 Recommended test equipment 16 4 Verification limits 16 5 Example reading limit calculation 16 5 Calculating resistance reading limits 16 5 Restori...

Страница 16: ...17 3 Calibration code 17 4 Front panel calibration code 17 4 Remote calibration code 17 4 Comprehensive calibration 17 5 Calibration cycle 17 5 Recommended equipment 17 5 Aborting calibration 17 6 Fr...

Страница 17: ...7753 V source A 9 Signal processing sequence C 2 Basic signal processing C 2 Signal processing using instrument features C 3 Signal processing using Ratio or Ch Avg C 6 Data flow remote operation C 7...

Страница 18: ...ds F 8 Addressed multiline commands F 8 Address commands F 9 Unaddress commands F 9 Common commands F 9 SCPI commands F 9 Command codes F 10 Typical command sequences F 12 IEEE command groups F 13 Int...

Страница 19: ...nt source calibration commands G 20 DATA G 20 SAVE G 21 Remote error reporting G 22 Error summary G 22 Error queue G 24 Status byte EAV Error Available bit G 24 Generating an SRQ on error G 24 Detecti...

Страница 20: ...s Summarizes the capabilities of the Keithley Models 7702 7751 7752 and 7753 switching modules QS1 Front and rear panel familiarization Summarizes the controls and connectors of the instrument QS2 Pow...

Страница 21: ...ates a connection terminal to the equipment frame The WARNING heading used in this manual explains dangers that might result in personal injury or death Always read the associated information very car...

Страница 22: ...annels of 4 pole input It also has two 2 pole channels used exclusively for current input Model 7751 This module has an on board programmable current source 0 to 50mA to test bridgewires and shunt bar...

Страница 23: ...k mount kits Model 4288 1 fixed rack mount kit Single unit rack mount kit Carrying case Model 1050 padded carrying case A carrying case for the Model 2790 includes handles and shoulder strap Model 279...

Страница 24: ...cal manipula tion of readings Also included are math functions to calculate low ohms when using the 7751 7752 7753 module and high ohms using the 7751 7753 module Relative Null offsets or establish ba...

Страница 25: ...Max3 2 4 wire Thermistor 4 wire RTD N A N A Latching electromechanical Oversized screw terminals Multiplexer2 All DMM functions 8 channels N A 8 channels 4 channels No Yes Connect no external sources...

Страница 26: ...instrument will operate as if the module is installed That is the Model 2790 will operate as if the pseudocard is installed klqb To avoid erratic operation it is not recommended to install or remove s...

Страница 27: ...SHIFT key and then the function operation key 1 Special keys and power switch SHIFT Use to select a shifted function or operation LOCAL Cancels GPIB remote mode POWER Power switch In position turns 2...

Страница 28: ...gs and buffer statistics Use the and keys to navigate through buffer FILTER Enables disables filter for selected function REL Enables disables relative for selected function and Dual function Manually...

Страница 29: ...ontinuity or limits testing Digital input output or analog output active set to non default value 4W 4 wire resistance or 4 wire RTD temperature reading displayed AC AC function selected ACV dB or ACI...

Страница 30: ...the INPUTS switch position SYSTem FRSWitch Query INPUTS switch 0 rear 1 front 6 Handle Pull out and rotate to desired position 7 Front panel inputs INPUT HI and LO Used for DCV ACV 2 CONT FREQ PERIOD...

Страница 31: ...onnector for IEEE 488 GPIB operation Use a shielded cable such as Models 7007 1 and 7007 2 5 Power module Contains the AC line receptacle power line fuse and line voltage setting The instrument can be...

Страница 32: ...e to the instrument possibly voiding the warranty 2 Before plugging in the power cord make sure that the front panel power switch is in the off O position Figure 1 3 Power module 3 Connect the female...

Страница 33: ...g fuse A rear panel fuse located next to the AC receptacle protects the power line input of the instrument If the line voltage setting needs to be changed or the line fuse needs to be replaced perform...

Страница 34: ...01 is the display board ROM revision Installed switching modules are then displayed For example if there is a Model 7751 installed in slot 1 and a Model 7752 installed in slot 2 the following messages...

Страница 35: ...ious states of operation See Front panel summary page 1 8 for a complete listing of display annunciators klqb The display test allows you to test display digit segments and annunciators The key test c...

Страница 36: ...OCAL key or sending GTL can cels the message and disables the text message mode DISPlay ENABle ON OFF Control display circuitry This command is used to enable and disable the front panel display circu...

Страница 37: ...terface The factory and RST default settings are listed in Table 1 4 Setting differences Set Diff between the two default setups are indicated by checkmarks For remote programming the SYSTem PRESet an...

Страница 38: ...present power on setup 5 Use the or key to display the desired setup and press ENTER The instrument returns to the normal measurement state Restoring a setup 1 Press SHIFT and then SETUP to access th...

Страница 39: ...ty Beeper On On Digits 4 digits 4 digits Range 1k 1k Rate Fast 0 1 PLC Fast 0 1 PLC Threshold level 10 10 Current AC and DC Bandwidth AC 30 30 Digits AC 5 digits 5 digits Digits DC 6 digits 6 digits F...

Страница 40: ...Off Off Reference 1 0 1 0 S1Iohms 7751 7752 and 7753 Off Off S2Iohms 7751 7752 and 7753 Off Off S1Vohms 7751 and 7753 Off Off S2Vohms 7751 and 7753 Off Off Monitor Off Off Output Beeper Never Never D...

Страница 41: ...effect No effect Timer Off Off Reading count No effect No effect Advanced scan Setup No effect No effect Immediate trigger On On Limit triggers Off Off Timer Off Off Reading count No effect No effect...

Страница 42: ...2790 to setup stored in memory location 2 Setting Factory RST Set Diff Voltage AC and DC dB Off Off Reference 1 0 1 0 Digits AC 5 digits 5 digits Digits DC 6 digits 6 digits Filter On Off Window 0 1 0...

Страница 43: ...nd word A query command requests queries the programmed status of that command When a query command is sent and Model 2790 is addressed to talk the response message is sent to the computer klqb For co...

Страница 44: ...ce the instrument in a non continuous measurement mode Most of the other settings for factory and RST defaults are the same For remote programming the following command is used to select function klqb...

Страница 45: ...ngs4 Press RECALL use edit keys to display readings Press EXIT to exit recall mode TRAC DATA 1 To avoid problems with remote programming it is good practice to routinely clear the buffer TRAC CLE at t...

Страница 46: ...ing a system channel connects the input to the DMM Input of the Model 2790 For a 4 wire function i e 4 a channel pair is connected to the DMM when a system channel is closed The system input channel i...

Страница 47: ...n the clist For example to close input channel 3 for a module in slot 1 the following command would be sent ROUTe CLOSe 103 2 Only the closed system channel is returned by ROUTe CLOSe The paired chann...

Страница 48: ...T OPEN ALL 2 Select 2 function Press 2 FUNC RES 3 Close system channel 201 Press the key Channel 1 connects to DMM Input ROUT CLOS 201 4 Close system channel 202 Press the key Channel 2 connects to DM...

Страница 49: ...1 5 shows the front panel keys used to close and open channels Figure 1 5 Front panel keys to close and open channels multiple channel operation For remote programming the following three commands are...

Страница 50: ...ultiple channel operation Front panel operation Command sequence 1 Open all channels Press OPEN display OPEN ALL Press OPEN ROUT OPEN ALL 2 Select 2 function Press 2 FUNC RES 3 Close channels to conne...

Страница 51: ...determines the number of scans to perform and is best explained by an example Assume there are 10 channels in the scan list i e 101 through 110 If you set the reading count to 10 or less one scan of...

Страница 52: ...N CHAN XXX INT SIMPLE Display SIMPLE option and press ENTER Specify minimum channel XXX and press ENTER SHIFT SCAN STEP CONFIG Press SHIFT Press CONFIG STEP MAX CHAN YYY Specify maximum channel YYY an...

Страница 53: ...3 Configure scan Press SHIFT press CONFIG select INT SIMPLE set MIN CHAN201 set MAX CHAN 208 select TIMER NO set RDG CT 000008 ROUT SCAN 201 208 SAMP COUN 8 4 Enable and start scan2 ROUT SCAN LSEL INT...

Страница 54: ...se 5 Trigger and return a single reading Exercise 6 Trigger and return multiple readings Exercise 7 Return a single reading continuous triggering Details on the commands to trigger and return readings...

Страница 55: ...N 1 SAMP COUN 1 Place 2790 in non continuous trigger state Set 2790 to perform one measurement 1 If a MATH function is enabled the result of the calculation will be returned MATH functions are covered...

Страница 56: ...are automatically stored in the buffer Statistics for buffer readings are also stored in the buffer CALC2 commands are used to calculate and return buffer statistics see Section 6 for details TRAC CL...

Страница 57: ...rigger state 1 If a MATH function is enabled the result of the calculation will be returned If there is no MATH function enabled FETCh and CALC DATA will return the basic reading MATH functions are co...

Страница 58: ...ber and switching module channel number System channel operation 7702 only Provides detailed information for using system channel operation Multiple channel operation Provides detailed information for...

Страница 59: ...unintended device under test connections In such system applications it is the system designer builders sole responsibility to ensure that under all such potential fault conditions no hazardous or da...

Страница 60: ...e channel operation the OVERFLOW message will not occur until the maximum voltage of the mainframe not module is exceeded Therefore the OVERFLOW message would occur only if 1010V is exceeded t okfkd C...

Страница 61: ...stallation t okfkd Slot covers must be installed on unused slots to prevent personal contact with high voltage circuits klqb Only one Model 7753 can be installed in a Model 2790 and it should be insta...

Страница 62: ...om unlimited energy sources NEVER connect an external source to the Model 2790 front panel inputs or a 7702 module t okfkd Dangerous arcs of an explosive nature in a high energy circuit can cause seve...

Страница 63: ...pseudocards SYSTem PCARd1 name Install pseudocard in slot 1 SYSTem PCARd2 name Install pseudocard in slot 2 name C7702 c7751 c7752 or c7753 Programming example The following command sets up the Model...

Страница 64: ...ed on the Model 2790 When a channel is not displayed there is no system channel When a measurement channel is closed the input backplane isolation channel also closes to connect the system channel to...

Страница 65: ...example of system channel connections for a 4 wire function Assume a Model 7702 switching module is installed in slot 2 of the mainframe and a 4 wire function such as 4 is selected When channel 201 i...

Страница 66: ...hannels available one of the following messages will be briefly displayed when one of these keys is pressed NO SCAN CARD This message indicates that there are no switching modules or pseudocards insta...

Страница 67: ...ule installed in the mainframe 2 With CLOSE SINGLE displayed press ENTER to display the prompt to close a channel CLOSE CH XXX 3 Using and key in the three digit channel you want to select 4 Press ENT...

Страница 68: ...stalled in slot 2 OPEN ALL will open all measurement channels 201 to 240 241 and 242 the backplane isolation channels 244 and 245 and the 2 pole 4 pole channel 243 Figure 2 2 shows the backplane isola...

Страница 69: ...command will result in error 222 Parameter data out of range b ROUTe CLOSe STATe clist This query returns a 0 open or 1 closed for every measurement channel specified in the clist For example assume...

Страница 70: ...Multiple channel operation allows individual control of each channel in the test system It allows any channel or channels in the test system to be closed or opened Channels for the 7751 7752 and 7753...

Страница 71: ...Never handle a switching module that is connected to an external source that is turned on Turn off all power sources before 1 making or breaking connections to the module and 2 installing or removing...

Страница 72: ...nu page 2 26 1 Press the CLOSE key and then use the or key to display the CLOSE MULTI message 2 Press ENTER to display the prompt to close a channel CLOSE MLT XXX 3 Using and key in the three digit ch...

Страница 73: ...ss the OPEN key The OPEN ALL message will be displayed 2 Press the or key to display the OPEN MULTI message 3 Press ENTER to display the prompt to open a channel OPEN MLT XXX 4 Using and key in the th...

Страница 74: ...specified in the clist only those listed channels will open Channels not specified are not affected c ROUTe OPEN ALL This command functions the same as the front panel OPEN key ALL menu option It sim...

Страница 75: ...this command to query channels 201 204 and 245 clist 201 204 245 The response message returns 0 0 1 to indicate that channels 201 and 204 are open and channel 245 is closed Remote programming example...

Страница 76: ...the DMM Input However the Model 2790 will not display the measurement channel that is closed It will display channel 201 instead of channel 202 1 Use the ALL option for the OPEN key to open all channe...

Страница 77: ...el 243 isolates channel 201 from channel 221 The Model 2790 will display the 1k reading for system channel 201 Remote programming ROUT CLOS 201 3 Using the MULTI option for the OPEN key open channel 2...

Страница 78: ...own in Figure 2 8 the closed position of channel 43 isolates Multiplexer A channels 1 through 20 from Multiplexer B channels 21 through 40 For the dual multiplexer configuration only Multiplexer A cha...

Страница 79: ...also connects the DUT to the external source This channel must remain closed while testing DUT Opening channel 44 isolates the external source from the backplane of the Model 2790 This channel must r...

Страница 80: ...T 1 H1 LO Ch 2 DUT 2 H1 LO Ch 20 DUT 20 H1 LO Ch 21 H1 LO Ch 22 H1 LO Ch 40 H1 LO Ch 43 Closed Ch 45 Ch 44 H1 LO Source Model 7702 Switching Module Model 2790 DMM The source could be the I source or V...

Страница 81: ...SE Select MULTI Key in 245 Press ENTER Remote programming ROUT MULT CLOS 243 245 3 Close channels 1 and 21 to connect DUT 1 to the DMM and bias supply Front panel operation Press CLOSE Select MULTI Ke...

Страница 82: ...witching Module Model 2790 Slot 2 Equivalent Circuit DUT 1 Ch 43 Closed HI LO HI LO HI LO HI LO HI LO DMM Mutliple channel operation Open all channels Close channel 243 Close channel 245 Close channel...

Страница 83: ...items and options and set parameter values With the desired item option or setting displayed press the ENTER key to select it You can cancel a pending selection and exit the menu structure by press in...

Страница 84: ...peed of the channel string is adjustable or can be paused The key slows down scrolling speed and the key speeds it up The ENTER key pauses scrolling Press ENTER a second time to resume scrolling Exiti...

Страница 85: ...f closed 7702 channels including the paired channel for 4 wire measurements It will not return non measurement channels For details see Table 2 1 and related reference information ROUT MULT CLOS is us...

Страница 86: ...remote operation The commands are summa rized in Table 2 3 Details follow the table klqb The relay closure count can be reset to zero For details see Section 18 of this manual Table 2 3 Relay closure...

Страница 87: ...the card only at a user set time interval which is initially set to 15 minutes at the factory or whenever the counts are queried Valid intervals set in integer number of minutes are between 10 and 14...

Страница 88: ...When closed the cable discharge circuit is connected across the input channels Used to dissipate charge build up due to capacitance in cables and signal paths Channel 21 Closing this channel connects...

Страница 89: ...4 LO Source Sense Ch 5 Bank 2 J102 A2 B2 Ch 6 HI Source Sense Ch 7 LO Source Sense Ch 8 Bank 3 J103 A3 B3 Ch 9 HI Source Sense Ch 10 LO Source Sense Ch 11 Bank 4 J104 A4 B4 Ch 12 Interlock Guard Guard...

Страница 90: ...imply the 7702 module can be used with EXTERNAL SOURCES i e non 7751 7753 derived above 300V DC peak rqflk To prevent damage to the Model 7702 switching module do not exceed these maximum signal level...

Страница 91: ...45 will close There is a 2 pole 4 pole relay channel 43 between channels 1 20 and channels 21 40 When a 2 wire function i e DCV is selected channel 43 opens 2 pole position to allow any of the 40 cha...

Страница 92: ...O Input Channel 43 2 Pole Open 4 Pole Closed see Note 3A 3A To Model 2790 Backplane Channel 45 see Note Backplane Isolation Channel 44 see Note Backplane Isolation Channels 43 through 45 in this schem...

Страница 93: ...an recall an individual Memory Pattern to close multiple channels and take a reading More importantly you can include Memory Patterns in a scan list and cause the Model 2790 to automatically scan thro...

Страница 94: ...is executed If any channels in clist are not valid analog output channels Error 221 Settings Conflict results c ROUTe MEMory DELay n NRf Assign a variable delay in seconds to memory pattern n This del...

Страница 95: ...ll memory pattern attributes will be associated to the reading klqb The ROUT MEM READ STAT command applies only to scanning You must include at least one measurement channel or a memory pattern that t...

Страница 96: ...ng Memory pattern scanning Once set up memory patterns can be automatically scanned in the same manner as 7702 module channels Section 7 has complete information on scanning Memory patterns program ex...

Страница 97: ...he source settings in the appropriate Memory Pattern for each individual test SOUR VOLT 500 128 Set V Source to 500V SOUR CURR 0 05 127 Set I Source 50mA Note Allow 250ms maximum settling time for V s...

Страница 98: ...lso shown below Setup Bridgewire A Test Memory Pattern Location 3 ROUT MEM CHAN 3 101 102 117 118 121 Specify relays to close ROUT MEM SOUR LEV 3 0 05 127 Set Isrc to 50mA for M3 since this source lev...

Страница 99: ...tter case the reading must be initiated explicitly as also shown below Setup Shunt Bar A Test Memory Pattern Location 5 ROUT MEM CHAN 5 101 102 112 117 118 121 Specify relays to close 112 is shunt bar...

Страница 100: ...Voltage Verification Memory Pattern Location 7 ROUT MEM CHAN 7 109 112 122 113 118 123 121 Specify relays to close 109 and 112 are shunt bars ROUT MEM SOUR LEV 7 500 128 Set Vsrc to 500V for M7 Since...

Страница 101: ...g scan during a scan the measurement is initiated automatically This does not apply when a memory pattern is recalled as shown below In the latter case the reading must be initiated explicitly as also...

Страница 102: ...tions being scanned These Trigger and Sample Count values cause memory locations to be scanned one time TRAC CLE Clear the nonvolatile data buffer TRAC POIN 9 Set buffer size to 9 readings TRAC FEED C...

Страница 103: ...ring with comma separators between the values The string will have to be parsed to obtain the individual readings The inspection process can actually be automated by assigning limits to the memory loc...

Страница 104: ...igure 2 14 Test setup for memory pattern test example 2790 Mainframe Ch 1 Ch 2 Ch 4 Ch 5 Ch 7 Ch 8 Bank 1 Bank 2 Bank 3 7751 7753 Module SEN LO SEN HI SRC LO SRC HI SRC HI SEN LO SEN HI SRC LO SRC HI...

Страница 105: ...2 48 Model 2790 SourceMeter Switch System Reference Manual...

Страница 106: ...asic DC and AC voltage measurements Current measurements DCI and ACI Provides detailed information for making basic DC and AC current measurements Resistance measurements 2 and 4 Provides detailed inf...

Страница 107: ...e wrong channel s is closed t okfkd An external source can be used with a 7702 module However when testing airbags or other devices that present a danger from unlimited energy sources NEVER connect an...

Страница 108: ...llation Category I and signal lines must not be directly connected to AC mains When making measurements in high energy circuits use test leads that meet the following requirements Test leads should be...

Страница 109: ...ternal voltages corresponding to offsets zero and amplifier gains These measurements are used in the algorithm to calculate the reading of the input signal This process is known as autozeroing When au...

Страница 110: ...itive going zero crossing of the power line cycle If the next trigger Trigger 2 occurs during the negative cycle then the measurement process also starts with the positive going zero crossing Figure 3...

Страница 111: ...onfiguration menu as explained in Section 7 For remote programming the clist parameter is used to config ure scan channels Channel list parameter clist SCH where S Mainframe slot number 1 or 2 CH Swit...

Страница 112: ...in the Model 2790 can also be scanned by using memory patterns see Memory patterns page 2 36 Each memory pattern location can have its own unique setup that includes channel s to close source level if...

Страница 113: ...voltage probe must be terminated to a 10M load The input divider cannot be enabled from the front panel For remote programming the following command controls the input divider VOLT IDIVider b Enable O...

Страница 114: ...z Input Resistance 10M on 1000V and 100V ranges 10G on 10V 1V and 100mV ranges CAUTION Maximum Input 1000V peak A DCV Connections B ACV Connections F F F 500V PEAK FRONT REAR 3A 250V AMPS HI INPUT LO...

Страница 115: ...and so on As shown in Figure 3 3C one DC voltage source is connected to a primary channel i e 104 and the other source is connected to its paired channel i e 124 klqb The ratio and channel average cal...

Страница 116: ...e to use with Model 7751 7753 Vsource t okfkd If both the front panel terminals and the switching module terminals are connected at the same time the test leads must be rated to the highest voltage th...

Страница 117: ...ow particularly for low level sources Improper shielding can cause the Model 2790 to behave in one or more of the following ways Unexpected offset voltages Inconsistent readings between ranges Sudden...

Страница 118: ...isplay 100 counts of offset on AC volts with the input shorted This offset is caused by the offset of the TRMS converter This offset will not affect reading accuracy and should not be zeroed out using...

Страница 119: ...out position For switching modules it must be in the R in position t okfkd To prevent electric shock never make or break connections while power is present in the test circuit Front panel inputs When...

Страница 120: ...measured rqflk Do not apply more than 3A to the input or the AMPS fuse will blow Model 7702 switching module When performing current measure ments the maximum allowable voltage is 60VDC or 30V RMS Exc...

Страница 121: ...hing module there are solder mount amps fuses See Section 18 of this manual for fuse replacement information Resistance measurements 2 and 4 The Model 2790 uses the constant current method to measure...

Страница 122: ...connect the test leads to INPUT HI and LO as shown in Figure 3 6A For 4 wire resistance 4 connect the test leads to INPUT HI INPUT LO SENSE 4 HI and SENSE 4 LO as shown in Figure 3 6B Figure 3 6 2 an...

Страница 123: ...aired to channel 21 channel 2 is paired to channel 22 and so on Figure 3 7 2 and 4 connections for Model 7702 switching module Shielding To achieve a stable reading it helps to shield resistances grea...

Страница 124: ...be measured rqflk Front panel inputs Do not apply more than 1000V peak between INPUT HI and LO or instrument damage may occur Model 7702 switching module Do not apply more than 300V DC or RMS between...

Страница 125: ...essing sequence page C 2 for details It includes a flowchart showing where in the processing sequence that the OCOMP operation is performed For a normal resistance measurement the Model 2790 sources a...

Страница 126: ...100 1k or 10k range or press AUTO to enable autorange If using autorange offset compensated ohms measurements will not be performed if the instrument goes to the 100k or higher range 4 Perform steps...

Страница 127: ...are used in the equation to calculate thermistor tempera ture The thermistor manufacturer s specified curve fitting constants may not be exactly the same as the ones used by the Model 2790 Appendix E...

Страница 128: ...e front panel inputs the INPUTS switch must be in the F out position For switching modules it must be in the R in position Thermistor connections A thermistor can be connected directly to the front pa...

Страница 129: ...ature from the temperature measurement configuration menu Use the following general rules to navigate through the menu structure Press SHIFT and then SENSOR to enter the menu structure Cursor position...

Страница 130: ...nfiguration The Alpha Beta Delta and at 0 C parameters for the five basic RTD types are provided in Table 3 3 Note that these parameters can be modified using remote programming Table 3 2 Thermistor t...

Страница 131: ...must be in the R in position 1 If a switching channel is presently closed displayed press OPEN to open it 2 Select the temperature measurement function by pressing TEMP 3 Configure the temperature mea...

Страница 132: ...l Frequency and period use a zero crossing trigger meaning that a count is taken when the frequency crosses the zero level The Model 2790 uses a reciprocal counting technique to measure frequency and...

Страница 133: ...puts the INPUTS switch must be in the F out position For switching modules it must be in the R in position Front panel input When using the front panel input terminals connect the test leads to the IN...

Страница 134: ...to select the function Press FREQ to perform frequency measurements Press SHIFT and then FREQ to perform period measurements 3 Use the RANGE and keys to select a measurement range consistent with the...

Страница 135: ...d display the resistance readings When the measured circuit is above the threshold level the message OPEN will be displayed klqb The reading rate for continuity is fixed at FAST 0 1 PLC Limits and dig...

Страница 136: ...eper will sound and the ohms reading will be displayed If the measurement is above the threshold level the message OPEN will be displayed 5 To disable continuity testing select a different function i...

Страница 137: ...Basic measurement commands Commands1 Description Default Ref Select measurement function SENSe 1 Optional root command FUNCtion name clist Select measurement function name VOLTage DC VOLTage AC CURRen...

Страница 138: ...ant for USER type NRf 0 to 0 01 0 00385 c TEMPerature FRTD BETA NRf clist Specify constant for USER type NRf 0 to 1 00 0 111 c TEMPerature FRTD DELTa NRf clist Specify constant for USER type NRf 0 to...

Страница 139: ...tional root command DATA LATest Returns the last reading string g DATA FRESh Returns the last fresh reading string g FETCh Return reading s g READ Trigger and return reading s g Channel list parameter...

Страница 140: ...hannel Details on scanning are provided in Section 7 b FRESistance OCOMpensated b clist The instrument does not have to be on the 4 function to enable offset compensated ohms When 4 is selected offset...

Страница 141: ...Tinuous OFF you can use the INITiate command to trigger one or more measurements klqb Note that sending INITiate while the instrument is performing measurements will cause error 213 init ignored SENSe...

Страница 142: ...to retrieve the reading strings With continuous initiation disabled INITiate CONTinuous OFF you can use the READ command to trigger and return readings The sample count determines the number of readi...

Страница 143: ...ng Example 3 temperature measurement using Model 7702 The following command sequence places the Model 2790 in a one shot trigger mode to per form a thermistor temperature measurement at channel 101 Mo...

Страница 144: ...the same reading over and over using this query It will continue to give the same result until one of two things has happened A new reading has been triggered The old reading has been invalidated by...

Страница 145: ...el is continuously initiating INIT CONT ON sending this query may cause a 213 Init ignored error but will still give a new reading When appropriate If the Model 2790 receives a RST command then it def...

Страница 146: ...r a reading to complete if a reading is in progress The CALC DATA FRESh query is similar to the DATA FRESh query but applies to readings which have math applied to them e g MX B scaling SENSe 1 DATA L...

Страница 147: ...speed TRIGger COUNt 1 READ Enter reading One shot reading DC volts bus trigger auto ranging RST INITiate CONTinuous OFF ABORt TRIGger SOURce BUS SENSe FUNCtion VOLTage DC SENSe VOLTage DC RANGe AUTO O...

Страница 148: ...ogramming Digits Provides details on selecting display resolution Includes the commands for remote programming Rate and bandwidth Provides details on integration rate and bandwidth for AC measurements...

Страница 149: ...yed FREQ and PERIOD Frequency measurements from 3Hz to 500kHz and period measurements from 2 s to 333 s can be made on the ACV ranges TEMP There is no range selection for temperature measurements Temp...

Страница 150: ...t automatically selects the best range to measure the applied signal Auto ranging should not be used when optimum speed is required Note that the AUTO key has no effect on temperature TEMP Up ranging...

Страница 151: ...AUTO b clist Control DCI auto range b ON or OFF ON CURRent AC RANGe UPPer n clist Select ACI range n 0 to 3 A 3 CURRent AC RANGe UPPer AUTO b clist Control ACI auto range b ON or OFF ON RESistance RAN...

Страница 152: ...e manually RANGe n When auto range is enabled the parameter value for RANGe n changes to the automatically selected range value When auto range is disabled the instru ment remains at the selected rang...

Страница 153: ...resolution To set display resolution press the DIGITS key until the desired number of digits is displayed Scanning 7702 only When a simple scan using a 7702 module is configured the present digits set...

Страница 154: ...ption Default SENSe 1 Optional root command VOLTage DC DIGits n clist Set of digits for DCV n 4 to 7 7 VOLTage AC DIGits n clist Set of digits for ACV n 4 to 7 6 CURRent DC DIGits n clist Set of digit...

Страница 155: ...the front panel 0 01 PLC from the bus results in increased reading noise and fewer usable digits while the slowest integra tion time 5 PLC from the front panel 50 PLC from the bus provides the best co...

Страница 156: ...he other functions will also set to medium speed For remote programming each function can have its own unique rate setting 0 01 to 50 or 60 PLC klqb Rate cannot be set for continuity It is fixed at 0...

Страница 157: ...6 6ms For remote program ming the integration rate can be set from 0 01 PLC to 50 or 60 PLC Table 4 4 lists the front panel bandwidth settings for the AC measurement functions For remote programming t...

Страница 158: ...2 5 0 TEMPerature APERture NRf clist Set rate for TEMP in secs NRf x to 13 Note 4 Bandwidth commands SENSe 1 Optional root command VOLTage AC DETector BANDwidth NRf clist Set AC bandwidth for ACV in H...

Страница 159: ...Hz klqb A rate command NPLCycles or APERture for ACV and ACI is only valid if the bandwidth for that AC function is set to 300 300Hz to 300kHz See Rate and bandwidth conflict error below for details R...

Страница 160: ...e digital filter places a specified number of A D conversions Filter Count into a memory stack These A D conversions must occur consecutively within a selected reading window Filter Window The reading...

Страница 161: ...erature reading The maximum temperature depends on which transducer is being used For example for a thermistor the maximum reading is 150 C a 10 window means that the filter window is 15 C Filter type...

Страница 162: ...stack The FILT annunciator will flash until 10 new readings fill the stack klqb Bit 8 of the Operation Event Status Register sets when the filter window has properly settled or the filter is disabled...

Страница 163: ...4 Use the and keys to display the number of readings to filter 1 to 100 and press ENTER 5 Use the or key to display the desired filter type moving or repeating and press ENTER The filter turns on and...

Страница 164: ...ively set to NONE and if the mov ing filter is selected the filter will not enable when the scan is run For the advanced scan filter state on or off and count can be set for each channel You cannot se...

Страница 165: ...nd VOLTage AC AVERage TCONtrol name Select filter type name MOVing or REPeat Note 2 VOLTage AC AVERage WINDow NRf Set filter window in NRf 0 to 10 0 1 VOLTage AC AVERage COUNt n clist Specify filter c...

Страница 166: ...EPeat Note 2 TEMPerature AVERage WINDow NRf Set filter window in NRf 0 to 10 0 1 TEMPerature AVERage COUNt n clist Specify filter count n 1 to 100 10 TEMPerature AVERage STATe b clist Enable or disabl...

Страница 167: ...ER WIND 0 01 Set filter window to 0 01 CURR AVER COUN 10 Set to filter 10 readings CURR AVER ON Enable filter Example 2 The following command sequence configures channels 101 through 115 of the Model...

Страница 168: ...ions for the 7751 7752 and 7753 modules Details on these math operations are provided in Section 2 of the Model 2790 User s Manual Ratio and channel average 7702 only Explains how to use these calcula...

Страница 169: ...that range For example on the 10V range the Model 2790 still overflows for a 12V input klqb The various instrument operations including Relative are performed on the input signal in a sequential mann...

Страница 170: ...can channel 101 is going to be configured for DCV and use rel select DCV and close channel 101 2 Apply the DCV signal to be rel ed to the closed channel This could be an offset or a baseline level 3 P...

Страница 171: ...clist Use input signal as rel value Rel commands for ACV SENSe 1 Optional root command VOLTage AC REFerence n clist Specify rel value n 757 5 to 757 5 V 0 VOLTage AC REFerence STATe b clist Enable dis...

Страница 172: ...r FREQ SENSe 1 Optional root command FREQuency REFerence n clist Specify rel value n 0 to 1 5e7 Hz 0 FREQuency REFerence STATe b clist Enable disable rel b ON or OFF OFF FREQuency REFerence ACQuire cl...

Страница 173: ...strument is on the DCV function the only valid acquire command is VOLT DC REF ACQ Also if the instrument is overflowed OVERFLOW or a reading has not been triggered an execution error 200 occurs when A...

Страница 174: ...he high ohms calculation is available Figure 5 1 shows the MATH menu tree Note that the settings shown in the menu tree are the factory defaults klqb The various instrument operations including Math a...

Страница 175: ...lt 3 Key in the scale factor value The and keys control cursor position and the and keys increment decrement the digit value To change range place the cursor on the multiplier and use the and keys m 0...

Страница 176: ...eading will be displayed 0 4 R klqbp The m and b constants for m X b are coupled to the m and b constants for mX b If you change any of the constants for m X b they will also change for mX b When usin...

Страница 177: ...and keys toggle polarity 4 Press ENTER to enter the m value and display the offset b value b 00 00000 m factory default 5 Key in the offset value 6 Press ENTER to enter the b value and display the on...

Страница 178: ...ys control cursor position and the and keys increment decrement the digit value To change range place the cur sor on the multiplier and use the and keys m 0 001 1 K 1000 and M 1 000 000 With the curso...

Страница 179: ...the Model 2790 It is the X variable for the calculation mX b When the SxIohms calculation is selected the Model 2790 measures voltage X and cal culates mX b using the above factors The displayed read...

Страница 180: ...X b 20 000 is the value of the feedback resistor RF for the I V amplifier RF 20k VMEAS is the measured voltage by the DMM of the Model 2790 It is the X variable for the calculation m X b When the SxV...

Страница 181: ...an nel s to connect the input to the DMM If using the front panel inputs FRONT inputs selected it does not matter if a switching channel is closed The result of the math calculation will be displayed...

Страница 182: ...1 KMATh MBFactor TRACk b Enable or disable source tracking3 OFF CALCulate 1 KMATh MBFactor SOURce name Selects source to be tracked name NONE S1ISource S2ISource S1VSource S2VSource NONE CALCulate 1...

Страница 183: ...ACQuire command When a reference value is set using PERCent NRf the PERCent query command returns the programmed value When reference is set using ACQuire the PERCent query com mand returns the acqui...

Страница 184: ...The following command sequence performs the mX b calculation for channels 101 and 102 of the Model 7702 Keep in mind that after CALC DATA is sent the Model 2790 has to be addressed to talk to send th...

Страница 185: ...paired to channel 22 and so on When ratio or channel average is enabled the Model 2790 measures the closed primary channel It then opens the primary channel and closes and measures the paired channel...

Страница 186: ...the result of the channel average calculation To disable channel average again press SHIFT and then CH AVG 5 When finished there are two ways to disable the calculation Press the OPEN key The calculat...

Страница 187: ...tails to configure and run a scan are provided in Section 7 Advanced scan configuration notes 1 When a calculation ratio or channel average is enabled for a primary scan channel the following setup ac...

Страница 188: ...This delay cannot be set from the front panel The 0 5s default delay keeps the relays from cycling too fast Setting a shorter delay may shorten the life of the relays It does not matter which of the...

Страница 189: ...d 125 FUNC VOLT 103 Set 103 for DCV RAT ON 103 Set 103 for ratio on FUNC VOLT 105 Set 105 for DCV CAV ON 105 Set 105 for channel average on dB Expressing DC or AC voltage in dB makes it possible to co...

Страница 190: ...Details on these commands follow the table klqb Queries are not included in Table 5 4 All the dB commands are provided in Table 15 11 Table 5 4 dB commands Commands Description Def DCV dB commands UN...

Страница 191: ...ect DCV function UNIT VOLT DB Select DCV dB UNIT VOLT DB REF 1V Set dB reference to 1V Example 2 The following command sequence configures channels 101 and 105 of the Model 7702 to perform ACV dB meas...

Страница 192: ...how to store and recall readings and discusses the various statistics available on buffer data including minimum and maximum values average mean standard deviation and peak to peak values Remote prog...

Страница 193: ...the processing sequence that buffer operations occur Front panel buffer Auto clear With buffer auto clear enabled the buffer is cleared readings lost before a new storage operation starts The buffer c...

Страница 194: ...ST front panel or remote operation However front panel FACTory defaults enables buffer auto clear Enabling disabling buffer auto clear 1 Press SHIFT and then SETUP 2 Use the and keys to display the pr...

Страница 195: ...the relative timestamp resets to 0 sec when the instrument is turned back on If you have readings stored in the buffer and auto clear is disabled when the unit is turned off subsequent stored reading...

Страница 196: ...lative REL or real time clock RTCL and press ENTER Storing readings Perform the following steps to store readings 1 Set up the Model 2790 for the desired configuration 2 Press the STORE key 3 Use the...

Страница 197: ...will increase by incrementing or decre menting the buffer reading number by 100 and then finally by 500 When you get close to the desired reading number release the or key Again press and hold in the...

Страница 198: ...The following equation is used to calculate mean where y is the average Xi is a stored reading n is the number of stored readings RDG NO 10 Reading Value Time Date RDG NO 9 Reading Value Time Date RDG...

Страница 199: ...ta store operation INIT and multi sample READ queries are locked out With readings in the buffer that were stored in that manner you cannot use the INIT or READ command if sample count is 1 error 225...

Страница 200: ...fer control name NEVer NEXT or ALWays NEV h TRACe DATA Read all readings in the buffer i TRACe DATA SELected start count Specify readings to be returned start starting point count number of readings j...

Страница 201: ...the timestamp will not clear the buffer SYSTem TSTamp TYPE and TRACe TSTamp TYPE Both of these commands query the timestamp type However SYSTem TSTamp TYPE queries the timestamp that will be used for...

Страница 202: ...math calculation For the CALCulate parameter the result of the calcula tion is stored in the buffer The NONE parameter disables storage into the buffer Math functions are covered in Section 5 klqb In...

Страница 203: ...cation for the next stored reading TRACe NEXT Query buffer location for next stored reading Assume that the above query returned value 37 Now you can use that value as the count parameter for the foll...

Страница 204: ...olute or DELTa timestamp as set by the TRACe TSTamp FORMat command FORMat ELEMents READing CHANnel UNITs RNUMber TSTamp LIMits Choose the elements to be outputted with each DATA or each buffer reading...

Страница 205: ...ndard deviation calculation is being performed on a buffer that has more than 1000 readings the CALCULATING message will flash to indicate that the Model 2790 is busy While busy with the calculation r...

Страница 206: ...annel program ming format the difference between sequential and non sequential scans and the basic scan process Block diagrams known as trigger models are provided to help explain the STEP and SCAN op...

Страница 207: ...Rd1 C7702 Install 7702 pseudocard in slot 1 SYSTem PCARd2 C7702 Install 7702 pseudocard in slot 2 Pseudocards for other switching modules can instead be installed Details on installing other pseudocar...

Страница 208: ...nned the unit backs up to scan channel 103 It then proceeds forward to scan channel 109 Any scan that performs backward scanning is considered a non sequential scan For more information on non sequent...

Страница 209: ...ions also use paired channels The scan process is to 1 open any closed channels 2 close the primary displayed channel and perform a measurement 3 open the pri mary channel 4 close the paired channel a...

Страница 210: ...o Figure 7 1 for STEP operation and Figure 7 2 for SCAN operation Figure 7 1 Trigger model with STEP function 7702 module Enable Scan Control Source Immediate External Timer Event Detection Output Tri...

Страница 211: ...ernal Timer Manual Bus Event Detection Another Scan Trigger Counter Yes No Close First Chan in List Open Last Chan Close Next Chan in List Ratio Chan Average Delay Measurement Process Device Action Ou...

Страница 212: ...the scan list is measured the Model 2790 outputs a trigger pulse If programmed to again scan the channels in the scan list the Model 2790 will wait at the control source for another trigger event Afte...

Страница 213: ...ng between scans It has no effect on the timing between scanned channels External trigger control source Pressing the EX TRIG key places the instrument in the external trigger mode TRIG annunciator on...

Страница 214: ...ult delay period is 0 5 sec onds but can be set from 0 to 999999 999 seconds using remote programming see Section 5 for details Ratio and channel average are covered in Section 5 klqb The Ratio Chan A...

Страница 215: ...example if channels 101 102 and 103 are programmed to be scanned the Sample Count is 3 Output trigger STEP operation After each channel is scanned an output trigger is applied to the rear panel Trigg...

Страница 216: ...scan configuration menu which is accessed by pressing SHIFT and then CONFIG Figure 7 3 shows the basic flowchart to configure a scan After entering the menu structure you can configure a simple scan a...

Страница 217: ...e setup As explained in Trigger models page 7 4 there is a user set delay auto or manual that is in effect for both the simple and advanced scan Channel setup considerations Rel In order to use an acq...

Страница 218: ...enus when a saved front panel scan is recalled The reading count value in the menu may not reflect the actual reading count of the scan For example Assume a Model 7702 module configured for a 10 chann...

Страница 219: ...nfigure a simple scan 1 While in the normal measurement mode set up the instrument for your test This setup will be used for all selected channels in the scan 2 Press SHIFT and then CONFIG to access t...

Страница 220: ...re RTD TEMP is selected The annunciators indicate which of the other instrument settings are enabled for the selected channel When you edit settings for the selected channel auto range rel rate etc th...

Страница 221: ...other channels are not affected Advanced scan setup procedure Step 1 Select the advanced scan configuration menu 1 Press SHIFT and then CONFIG to access the scan setup menu 2 Press the or key to displ...

Страница 222: ...EP or SCAN key Use the or key to display IMM SCAN Y and press ENTER klqb Disable immediate scan IMM SCAN N when you wish to use a monitored reading limit to trigger the start of the scan This techniqu...

Страница 223: ...TRIGger DELay AUTO b commands are used to set the delay See Table 7 1 for details klqb The delay for ratio and channel average can only be set using remote program ming Table 5 3 Monitor channel While...

Страница 224: ...he monitor 2 Press SHIFT and then MONITOR MON annunciator turns on Method 2 1 If a channel is closed press OPEN to open it 2 Press SHIFT and then MONITOR 3 Use the and keys to display the monitor chan...

Страница 225: ...rn to the normal measurement state klqbp Auto channel configuration cannot be enabled if there is a non scan channel presently closed For example assume the scan list consists of channels 105 through...

Страница 226: ...power on setup Scan operation 7702 only A basic scan is controlled solely by the STEP and SCAN keys When one of these keys is pressed the STEP or SCAN operation will be performed For the manual extern...

Страница 227: ...for each channel For example assume one channel used OCOMP ohms while a second used 2 When the readings are recalled the OCOMP annunciator may remain on for both channels This display anomaly is due...

Страница 228: ...l 2790 goes into the idle state If you wish to repeat the scan sequence you will have to first take the Model 2790 out of idle This can be done by pressing the STEP or TRIG key SCAN operation In gener...

Страница 229: ...er the start of the scan Perform the following steps to run a monitor scan klqb The last enabled scan function STEP or SCAN will be used for the monitor scan 1 Perform Step 1 and Step 2 of the Advance...

Страница 230: ...OUTe MONitor POINts com mand to specify the number of channels to scan Table 7 1 4 While in the normal measurement state select and enable the monitor channel as explained in Monitor channel page 7 18...

Страница 231: ...to initiate one scan cycle include INITiate Initiate one scan cycle READ Initiate one scan cycle and request sample readings More information on using these commands is provided by Reference f that f...

Страница 232: ...ont panel data store opera tion must be cleared before sending INITiate or READ to take the instrument out of idle The following command clears the buffer TRACe CLEar Clear buffer 7751 7752 7753 modul...

Страница 233: ...tern scanning Enable Scan Control Source Immediate External Timer Manual Bus Event Detection Another Scan Trigger Counter Yes No Make Measurement Output Trigger Another Location Yes No Sample Counter...

Страница 234: ...scan b ON or OFF Note 1 ROUTe SCAN LSELect name Enable disable scan name INTernal on or NONE off NONE ROUTe MONitor clist Specify one channel to be monitored c ROUTe MONitor POINts NRf Specify number...

Страница 235: ...55000 1 e SAMPle COUNt Query sample count INITiate CONTinuous b Enable disable continuous initiation b ON or OFF f INITiate Initiate one scan cycle f READ Initiate one scan cycle and request sample re...

Страница 236: ...ed to be performed using remote pro gramming Unexpected results may occur if a non sequential scan is run from the front panel There must be at least two channels in the scan list Creating a scan list...

Страница 237: ...an list If it is not the first channel in the scan list will auto matically become the monitor channel If the clist has more than one channel error 223 too much data occurs and the command is not exec...

Страница 238: ...ontrol source TRIG COUN 1 Set to perform one scan SAMP COUN 10 Set to scan 10 channels ROUT SCAN 101 110 Set scan list channels 101 through 110 ROUT SCAN TSO IMM Start scan when enabled and triggered...

Страница 239: ...fer Each time the scan is run the two readings will be appended added to the buffer A thermistor is used to measure temperature The thermistor is connected directly to the screw terminals of the switc...

Страница 240: ...del 2790 SourceMeter Switch System Reference Manual 7 35 Figure 7 5 External trigger scan example 2 Measurements Measure Open Last Chan Close Next Chan No Yes Wait For Trigger Close Chan 101 Enable Sc...

Страница 241: ...el 101 Select TEMP function FUNC TEMP 101 Configure temperature SHIFT SENSOR Select thermistor sensor SENS THRMSTR TEMP TRAN THER 101 Select thermistor type TYPE 5000 TEMP THER 5000 101 b Channel 102...

Страница 242: ...on is shown in Figure 7 6 while the procedure steps and programming commands are listed in Table 7 3 In Figure 7 6 notice that there are two modes of operation While in the monitor mode the Model 2790...

Страница 243: ...stem Reference Manual Figure 7 6 Monitor scan example 30 C 4 Measurements Measure TEMP Close Monitor Channel 101 No Yes Measure Open Last Chan Close Next Chan Close First Channel Return to Monitor Mod...

Страница 244: ...limit 1 Set limit to 30 SHIFT LIMITS HI1 30 00000 CALC3 LIM1 UPP 30 101 Enable on limit SHIFT OFF ON LIMITS ON CALC3 LIM1 STAT ON 101 Enable Channel Average SHIFT CH AVG CAV ON 101 Close channel 1 RO...

Страница 245: ...7 40 Model 2790 SourceMeter Switch System Reference Manual...

Страница 246: ...ettle Explains the Reading Hold feature which is used to screen out readings that are not within a specified reading window External triggering Explains external triggering which allows the Model 2790...

Страница 247: ...fault setup the instru ment will not stay in idle Operation will continuously fall through the idle state and pro ceed to the Event Detection block of the trigger model When in the one shot trigger mo...

Страница 248: ...auto or manual A programmable delay is available after event detection It can be set manually or an auto delay can be used With auto delay selected the instrument automatically selects a delay period...

Страница 249: ...ote that pressing the AUTO key sets the delay to 0 001 sec Press ENTER to accept the delay or EXIT for no change Table 8 1 Auto delay settings Function Range and delay DCV 100mV 1ms 1V 1ms 10V 1ms 100...

Страница 250: ...it is rejected and operation loops back to the beginning of the Device Action in Figure 8 2 The hold count specifies how many readings have to be within the window before it is accepted See Reading ho...

Страница 251: ...ing is held on the display until an out of window reading occurs to restart the hold process For remote operation the hold process seeks a new seed once it has been satisfied and the reading has been...

Страница 252: ...es are displayed to indicate the instrument is waiting for an external trigger From the front panel press the TRIG key to trigger a single reading Pressing the EX TRIG key again toggles back to contin...

Страница 253: ...h 5V input triggers are enabled When pulled low to 0V input triggers are disabled When disabled the Model 2790 will not respond to an input trigger Details on the Digital I O are provided in Section 9...

Страница 254: ...an be used to trigger other instruments The specifications for this trigger pulse are shown in Figure 8 5 Typically you would want the Model 2790 to output a trigger after the settling time of each me...

Страница 255: ...shown in Figure 8 6 Figure 8 6 DUT test system DUT 1 DUT 400 DUT 2 OUTPUT Card 1 1 2 400 10 7011 MUX Cards Model 2790 F F Model 2790 SourceMeter Switch System RANGE F 500V PEAK FRONT REAR 3A 250V AMP...

Страница 256: ...ored Scan list 1 1 1 400 Number of scans 1 Channel spacing TrigLink Figure 8 7 Trigger link connections Model 2790 KEITHLEY SLOT COVER DIGITAL I O TRIG LINK RS232 CARD 1 CARD 2 CARD 3 CARD 4 CARD 5 CA...

Страница 257: ...triggering example A Pressing EX TRIG on the Model 2790 places it at point A in the flowchart where it is waiting for an external trigger B Pressing STEP on the Model 7002 takes it out of the idle sta...

Страница 258: ...riggers the Model 2790 to measure the next DUT The process continues until all 400 channels are scanned measured and stored in the buffer External triggering with BNC connections An adapter cable is a...

Страница 259: ...TAL I O TRIG LINK RS232 8503 DIN to BNC Trigger Cable INPUT OUTPUT Model 220 Current Source External Trigger WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY CAUTION F...

Страница 260: ...state the instrument cannot perform any measure or step scan operations The following commands will return operation to the top of the trigger model idle at the START point of the trigger model ABORt...

Страница 261: ...IMM or INIT CONT ON No Yes Idle and Initiate Trigger Source Immediate Trigger Source External Trigger Source Timer Trigger Source Manual Trigger Source BUS Trigger Delay n Trigger Delay AUTO b Another...

Страница 262: ...erwise the length of the delay is controlled by the user set Delay period The Timer interval can be set from 0 to 999999 999 seconds The timer resets to its initial state when the instrument goes into...

Страница 263: ...trigger cycle b INITiate CONTinuous b Enable disable continuous initiation ON or OFF Note 1 c FETch Request the last reading s d READ Perform an ABORt INITiate and a FETch d TRIGger SOURce name Selec...

Страница 264: ...ger DELay AUTO b The auto delay times are listed in Table 8 1 Disabling auto delay sets the delay time to 0 g TRIGger SIGNal Send this action command to bypass the control source when you do not wish...

Страница 265: ...8 20 Model 2790 SourceMeter Switch System Reference Manual...

Страница 266: ...tputs respond to the results of limit tests Remote programming limits and digital output Summarizes the com mands to perform limit tests and control the digital I O port Application sorting resistors...

Страница 267: ...its which are the factory defaults Limit 1 HI1 1V and LO1 1V Limit 2 HI2 2V and LO2 2V Keep in mind that a limit value for Limit 2 does not have to exceed the Limit 1 value For example Limit 2 can be...

Страница 268: ...beeper is also available for limit testing There are three beeper options NEVER OUTSIDE and INSIDE These options are explained as follows NEVER With this option the beeper is disabled OUTSIDE With thi...

Страница 269: ...ction Setting limits 1 Press SHIFT and then LIMITS to display the high limit for Limit 1 HI1 2 Use and to key in the HI1 limit and press ENTER 3 When editing a reading use the range designator K or M...

Страница 270: ...triggering Pin 6 is physically connected to the input line pin 2 of the TRIG LINK connector Pin 8 of the digital I O is used to enable or disable Trigger In Trigger In is enabled by leav ing pin 8 op...

Страница 271: ...controlled by limit operations Each of these five outputs correspond to the following limit operations Digital Output 1 Low Limit 1 LO1 Digital Output 2 High Limit 1 HI1 Digital Output 3 Low Limit 2...

Страница 272: ...e programming Pulse time cannot be set from the front panel klqb The commands to set pulse time and enable disable pulse output are listed in Table 9 2 See Digital output commands in the table The pul...

Страница 273: ...5V and 33V and the current required by the device does not exceed 250mA rqflk On pin 7 do not exceed 33V For the output lines do not exceed the maximum sink current The maximum sink current for an out...

Страница 274: ...puts to active TTL low power TTL or CMOS inputs For this mode of operation the output lines can source up to 200 A 4 75k Pull Up Resistor Pin 9 Digital Ground Digital Output Pin 7 Diode Clamp Relay Co...

Страница 275: ...or switch open to provide a reli able logic high output 3 75V When the output line goes low the transistor turns on transistor switch closed to route current to digital ground As a result a low logic...

Страница 276: ...r limit latch When enabled the master limit remains latched when a reading limit is reached or exceeded When disabled the master limit line releases immediately when the reading is inside all four lim...

Страница 277: ...ess ENTER 7 Use the key to display the present PULSE mode setting NO or YES 8 To retain the present pulse mode setting press ENTER Otherwise press to move the cursor to the right press the or key to d...

Страница 278: ...Enable disable Limit 1 test b ON or OFF a CALCulate3 LIMit1 FAIL Query test result 0 pass in 1 fail high or low b CALCulate3 LIMit1 CLEar Clear fail indication c CALCulate3 LIMit1 CLEar AUTO b Enable...

Страница 279: ...reaches or exceeds the high or low limit the HIGH or LOW annunciator will turn on and the number 2 will be displayed klqb When limits are disabled from the front panel both Limit 1 and Limit 2 disable...

Страница 280: ...ons for Limit 1 and Limit 2 If auto clear is enabled for a limit the fail indication clears when instrument opera tion enters the idle state With auto clear disabled the fail indication will remain un...

Страница 281: ...ceed 5 tolerance The digital outputs of the Model 2790 can be used to further automate the test system by controlling a compatible component handler to perform the binning operations Limits Limit test...

Страница 282: ...5 The limits are illustrated in Figure 9 7 Figure 9 7 Limits to sort 100 resistors 1 5 and 5 Front Panel Operation For front panel operation the INSIDE beeper mode must be used A normal pitch beep and...

Страница 283: ...command Digital outputs With the digital outputs of the Model 2790 enabled the digital outputs will respond as fol lows for each resistor reading Limit 1 result Limit 2 result Resistor tolerance Bin...

Страница 284: ...address selection and bus connections General bus commands Describes general bus commands used for fundamental GPIB control Front panel GPIB operation Summarizes GPIB error messages status indicators...

Страница 285: ...is part of the normal measurement process to assure stable accurate measure ments Autozero can be disabled to increase measurement speed However the readings will eventually become inaccurate over ti...

Страница 286: ...ROUTe MULTiple commands you gain independent control of all switching module channels including the relays that con nect the input signal to the DMM See Section 2 for details GPIB setup The following...

Страница 287: ...B key The GPIB ON or GPIB OFF message will be displayed 2 If the GPIB is already ON press ENTER and proceed to step 3 Otherwise press the key to place the cursor on OFF press the or key to display the...

Страница 288: ...nt screws which are silver colored Do not use these types of connectors on the Model 2790 it is designed for metric threads Figure 10 2 shows a typical connecting scheme for a multi unit test system F...

Страница 289: ...ed with an IEEE 488 style connector but a few may require a different type of connecting cable See your controller s instruction manual for information about properly connecting to the IEEE 488 bus kl...

Страница 290: ...instrument in the remote state You must address the instrument to listen after setting REN true before it goes into remote The Model 2790 must be in remote in order to use the following commands to tr...

Страница 291: ...essing LOCAL will not restore control to the front panel The GTL command restores control to the front panel Cycling power will also cancel local lockout GTL go to local Use the GTL command to put a r...

Страница 292: ...rmed at any time to obtain the status byte from the Model 2790 Front panel GPIB operation This section describes aspects of the front panel that are part of GPIB operation including messages status in...

Страница 293: ...ten addressing it to talk or sending IFC Interface Clear command over the bus SRQ You can program the instrument to generate a service request SRQ when one or more errors or conditions occur When this...

Страница 294: ...d optional and does not have to be used Thus the above command can be sent in one of two ways INITiate or INITiate IMMediate Notice that the optional command is used without the brackets When using op...

Страница 295: ...ENABle 110 222 Enable errors 110 through 222 Angle brackets Angle brackets are used to denote a parameter type Do not include the brackets in the program message For example RATio b The b indicates a...

Страница 296: ...long form SYST PRES short form SYSTem PRES long form and short form combination Note that each command word must be in long form or short form and not something in between For example SYSTe PRESe is...

Страница 297: ...s STATus Path Root OPERation Path ENABle NRf Command and parameter ENABle Query command PRESet Command Single command messages The above command structure has three levels The first level is made up o...

Страница 298: ...command word on the next level as the root For fastest operation do not send optional data A colon can be used at the beginning of a program message However using the colon slows down execution time E...

Страница 299: ...n the Output Queue When the Model 2790 is then addressed to talk the response message is sent from the Output Queue to the computer Multiple response messages If you send more than one query command i...

Страница 300: ...r you connect to the multimeter also uses these settings You can break data transmissions by sending a C decimal 3 or X decimal 18 charac ter string to the instrument This clears any pending operation...

Страница 301: ...d after the CR character is received from the controller klqb For RS 232 operation OPC or OPC should be used with slow responding commands A list of the slowest responding commands and details on OPC...

Страница 302: ...e key to place the cursor on OFF press the or key to display the ON state and then press ENTER klqb Enabling ON the RS 232 interface disables OFF the GPIB Disabling the RS 232 interface enables the GP...

Страница 303: ...the rear panel connector for the RS 232 interface and Table 10 2 shows the pinout for the connector If your computer uses a DB 25 connector for the RS 232 interface you will need a cable or adapter wi...

Страница 304: ...mputer PC Error messages See Appendix B for RS 232 error messages 800 through 808 Table 10 3 PC serial port pinout Signal DB 9 pin number DB 25 pin number DCD data carrier detect 1 8 RXD receive data...

Страница 305: ...10 22 Model 2790 SourceMeter Switch System Reference Manual...

Страница 306: ...er in the status structure Status byte and service request SRQ Explains how to program the Status Byte to generate service requests SRQs Shows how to use the serial poll sequence to detect SRQs Status...

Страница 307: ...ogrammed by the user the RQS MSS bit will set to indicate that an SRQ has occurred Status register sets A typical status register set is made up of a condition register an event register and an event...

Страница 308: ...Enable Register Questionable Condition Register Questionable Event Register 0 2 3 5 6 Cal 7 11 12 13 15 1 Temp Warn 0 2 3 5 6 Cal 7 11 12 13 15 1 Temp Warn 0 2 3 5 6 Cal 7 11 12 13 15 1 Temp Warn Outp...

Страница 309: ...tion Notes Reset registers CLS Reset all bits of the following event registers to 0 1 Standard Event Register Operation Event Register Measurement Event Register Questionable Event Register STATus PRE...

Страница 310: ...ns of the register Figure 11 2 indicate the binary parameter value For example if you wish to set bits B4 B3 and B1 the binary value would be 11010 where B4 1 B3 1 B1 1 and all other bits are 0 The bi...

Страница 311: ...are set 1 Status byte and service request SRQ Service request is controlled by two 8 bit registers the Status Byte Register and the Ser vice Request Enable Register Figure 11 3 shows the structure of...

Страница 312: ...ent in the Error Queue Bit B3 Questionable Summary Bit QSB Set summary bit indicates that an enabled questionable event has occurred Bit B4 Message Available MAV Set summary bit indicates that a respo...

Страница 313: ...set bit B6 and generate an SRQ service request In your test program you can periodically read the Status Byte to check if an SRQ has occurred and what caused it If an SRQ occurs the program can for ex...

Страница 314: ...valid command is sent line 3 bits B2 EAV and B6 MSS of the Status Byte Register set to 1 The last command reads the Status Byte Register Keep in mind that you have to address the Model 2790 to talk af...

Страница 315: ...ls that are equivalent to the initialize transmit send srq and spoll calls used below SRQ when buffer fills with 500 1000 1500 and 1750 readings The following program will store 2000 readings in the b...

Страница 316: ...Disable standard events CALL send addr sre 1 status Enable measurement events CALL send addr init status Start measure store process N 0 Initialize quarter buffer counter WaitSRQ WHILE srq 0 WEND Wai...

Страница 317: ...that all pending selected device operations are completed and the Model 2790 is ready to accept new com mands This bit only sets in response to the OPC query command See Section 12 for details on OPC...

Страница 318: ...ror 520 Saved setup scancard mismatch Settings for a user setup or power on setup do not match the switching module types presently installed For details see Defaults and user setups page 1 18 Error 5...

Страница 319: ...et bit indicates that the filter has settled or the filter is disabled Bit B9 Not used Bit B10 Idle State Idle Set bit indicates the Model 2790 is in the idle state Bits B11 through B15 Not used Figur...

Страница 320: ...eadings have been stored in the buffer The TRACe NOTify command specifies the number of stored readings that will set this bit see Section 6 for details Bit B7 Buffer Available BAV Set bit indicates t...

Страница 321: ...F B9 BHF B8 BAV B7 BN B6 RAV B5 HL2 B4 LL2 B3 HL1 B2 LL1 B1 ROF B0 OR To Measurement Summary Bit MSB of Status Byte Register ML Master Limit BTF Buffer Three quarter Full BQF Buffer Quarter Full HL Ha...

Страница 322: ...will instead use a default calibration constant This error will clear after successful calibration of the instrument Bit B9 Slot 1 Interlock Open Int1 Set bit indicates that the interlock for the modu...

Страница 323: ...etails on read ing registers see Reading registers page 11 6 Table 11 3 Condition register commands Command Description STATus OPERation CONDition Read Operation Condition Register STATus MEASurement...

Страница 324: ...CLS resets all four event registers The commands to read the event registers are listed in Table 11 4 For details on reading registers see Reading registers page 11 6 Table 11 4 Event register comman...

Страница 325: ...set to 1 Attempting to do so will generate a 222 Parameter data out of range error Programming example program and read register set The following command sequence programs and reads the measurement r...

Страница 326: ...iate query is sent Error queue The Error Queue holds error and status messages When an error or status event occurs a message that defines the error status is placed in the Error Queue When a message...

Страница 327: ...removed from the enabled list klqb To prevent all messages from entering the Error Queue send the enable com mand along with the null list parameter as follows STATus QUEue ENABle Programming example...

Страница 328: ...12 CommonCommands...

Страница 329: ...r all pending commands have been executed B OPC Operation complete query Places an ASCII 1 into the output queue when all pending selected device operations have been completed C OPT Option query Retu...

Страница 330: ...used with the immediate initiation command INITiate the OPC bit in the Standard Event Status Register will not set until the Model 2790 goes back into the idle state The INIT command operation is not...

Страница 331: ...t to the computer The 1 in the Output Queue will set the MAV Message Available bit B4 of the Status Byte Register If the corresponding bit B4 in the Service Request Enable Register is set the RQS MSS...

Страница 332: ...d SYST PRES RCL and SAV ROUT MULT CLOS and ROUT MULT OPEN Only if the clist is long CALC2 IMM Only when performing the standard deviation calculation on a large buffer A 10 000 point buffer takes appr...

Страница 333: ...up memory If a recall error occurs the setup memory defaults to the SYSTem PRESet values klqb For RS 232 operation OPC or OPC should be used with SAV and RCL which are slow responding commands Details...

Страница 334: ...el 2790 to be controlled by bus triggers The last line which sends a bus trigger triggers one measurement Each subsequent bus trigger will also trigger a single measurement RST Restore RST defaults TR...

Страница 335: ...ot considered complete until the Model 2790 returns to idle By sending the WAI command after the INITiate command all subsequent commands will not execute until the Model 2790 goes back into idle The...

Страница 336: ...13 SCPISignalOriented MeasurementCommands...

Страница 337: ...le 13 1 Signal oriented measurement command summary Command Description CONFigure function rang res clist FETCh READ MEASure function rang res clist Places the Model 2790 in a one shot measurement mod...

Страница 338: ...ax error If only one parameter is used and it is not a clist it is interpreted as the range parameter rang If two parameters are used and the second one is not a clist the first parameter is the range...

Страница 339: ...ution of the res parameter value and the selected range sets the number of display digits As shown above with the 100V range selected and res 0 1 a 100V reading will be displayed as 100 0 V 3 digits T...

Страница 340: ...command to trigger a measurement and acquire a reading see READ When this command is sent without the clist parameter the Model 2790 will be configured as follows The function specified by this comma...

Страница 341: ...der to return multiple reading strings continuous initiation must be disabled INIT CONT OFF so that the sample count SAMPle COUNt which specifies the number of measurements to be performed can be set...

Страница 342: ...initiation is enabled the READ command will generate error 213 init ignored It can be disabled by sending INITiate CONTinuous OFF The RST command can also be used to disable continuous initiation It a...

Страница 343: ...additional information res 0 1 i e 100 0 V 3 digits 0 01 i e 10 00 V 3 digits 0 001 i e 1 000 V 3 digits 0 0001 i e 1 0000 V 4 digits 0 00001 i e 1 00000 V 5 digits 0 000001 i e 1 000000 V 6 digits Th...

Страница 344: ...command is sent the following commands execute in the order that they are presented ABORt CONFigure function READ When ABORt is executed the instrument goes into the idle state if con tinuous initiati...

Страница 345: ...13 10 Model 2790 SourceMeter Switch System Reference Manual...

Страница 346: ...MatandMiscellaneous SYSTemCommands FORMat commands Covers the SCPI commands to configure the format for readings that are sent over the bus Miscellaneous SYSTem commands Covers miscellaneous SYSTem co...

Страница 347: ...LC2 DATA over the GPIB can be returned in either the ASCii or binary format All other queries are returned in ASCii regardless of the selected format Over the RS 232 interface only the ASCII format is...

Страница 348: ...e 14 6 for information on the data elements Figure 14 1 also shows the byte order of the data string Data elements not specified by the ELEMents command are simply not included in the string Figure 14...

Страница 349: ...locks Note that the data string for each reading conversion is preceded by a 2 byte header that is the binary equivalent of an ASCII sign and 0 Figure 14 2 does not show the byte for the terminator th...

Страница 350: ...er Byte 4 Byte 3 Byte 2 Byte 1 The Header is only sent once for each measurement conversion A Single precision data format 32 data bits s 0 7 0 7 0 7 0 7 0 e f Header Byte 1 Byte 2 Byte 7 Byte 8 Bytes...

Страница 351: ...Select timestamp type RELative or RTCL klqb The real time clock timestamp can only be returned for the ASCII data format For the binary formats timestamp will not be sent with the real time clock sel...

Страница 352: ...d to its binary equivalent is1010 That means High Limit 2 and High Limit 1 have failed FORMat BORDer name Parameters NORMal Normal byte order for IEEE 754 binary format SWAPped Reverse byte order for...

Страница 353: ...should be used with SYST PRES which is a slow responding command Details on OPC and OPC are provided in Section 12 SYSTem VERSion Read the version of the SCPI standard being used by Model 2790 Example...

Страница 354: ...for limits and continuity tests However when limits or CONT is again selected the beeper will automatically enable Parameters b 0 Disable beeper 1 Enable beeper Figure 14 3 Key press codes 1 2 3 4 5...

Страница 355: ...14 10 Model 2790 SourceMeter Switch System Reference Manual...

Страница 356: ...15 SCPIReferenceTables...

Страница 357: ...are used to indicate parameter type Do not use angle brackets in the program message The Boolean parameter b is used to enable or disable an instrument operation 1 or ON enables the operation and 0 or...

Страница 358: ...Set m factor for mX b and m X b 4294967295 to 4294967295 1 1 MMFactor clist Query m factor 1 MA1Factor clist Query m factor 1 MBFactor NRf clist Set b factor for mX b and m X b 4294967295 to 42949672...

Страница 359: ...uery state of limit outputs PULSe Path to control limit output pulsing STATe b Enable or disable limit output pulsing OFF STATe Query state of limit output pulsing TIME NRf Set output pulse time in se...

Страница 360: ...A clist Query lower limit STATe b clist Enable or disable limit test OFF STATe clist Query state of limit test FAIL Query test result 1 failing CLEAR Path to clear events IMMediate Clear high and low...

Страница 361: ...ON ENABle Query state of the display Note RST and SYSTem PRESet have no effect on commands in this subsystem The listed defaults are power on defaults Table 15 3 FORMat command summary Command Descrip...

Страница 362: ...Nt clist Query closure count for specified channels Sec 2 INTerval NRf Set count update interval in minutes 10 to 1440 Note 3 INTerval Query relay count update interval CLOSe Returns a clist of closed...

Страница 363: ...ery channel pattern for memory n SOURce LEVel n NRf clist Assign source values to channels Note 5 LEVEL n Query source values DELay n NRf Assign a variable delay to memory n Note 5 DELay n Query delay...

Страница 364: ...COUNt Query Hold count STATe NRf Enable or disable Hold OFF STATe Query state of Hold CAVerage b clist Channel average calculation 7702 only Sec 5 DELay NRf clist Set delay between the two measurement...

Страница 365: ...reference 1010 to 1010 0 Sec 5 STATe b clist Enable or disable reference OFF STATe clist Query state of reference ACQuire clist Use input signal as reference REFerence clist Query reference value AVE...

Страница 366: ...7 5 0 Sec 5 STATe b clist Enable or disable reference OFF STATe clist Query state of reference ACQuire clist Use input signal as reference REFerence clist Query reference value AVERage Path to configu...

Страница 367: ...ist Query resolution REFerence n clist Specify reference 3 1 to 3 1 0 Sec 5 STATe b clist Enable or disable reference OFF STATe clist Query state of reference ACQuire clist Use input signal as referen...

Страница 368: ...0 Sec 5 STATe b clist Enable or disable reference OFF STATe clist Query state of reference ACQuire clist Use input signal as reference REFerence clist Query reference value AVERage Path to configure a...

Страница 369: ...clist Query resolution REFerence n clist Specify reference 0 to 120e6 0 Sec 5 STATe b clist Enable or disable reference OFF STATe clist Query state of reference ACQuire clist Use input signal as refe...

Страница 370: ...erence 0 to 120e6 0 Sec 5 STATe b clist Enable or disable reference OFF STATe clist Query state of reference ACQuire clist Use input signal as reference REFerence clist Query reference value AVERage P...

Страница 371: ...erence ACQuire clist Use input signal as reference REFerence clist Query reference value AVERage Path to configure and control filter Sec 4 TCONtrol name Select filter type MOVing or REPeat Note 3 TCO...

Страница 372: ...clist Query delta FREQuency Path to configure frequency Sec 3 APERture NRf clist Sets gate time for frequency measurements in seconds 0 01 to 1 0 1 0 Sec 4 APERture clist Query frequency gate time DI...

Страница 373: ...threshold voltage range Sec 3 VOLTage RANGe n clist Select threshold range 0 to 1010 10 RANGe clist Query threshold range CONTinuity Path to configure continuity test Sec 3 THReshold NRf Set threshold...

Страница 374: ...ist Set V source output 50 to 500 V clist 128 Slot 1 228 Slot 2 50 AMPLitude clist Query V source output level SOURce CURRent LEVel IMMediate AMPLitude NRf clist Set I source output 0 to 50 mA clist 1...

Страница 375: ...egister CONDition Read the condition register PRESet Return status registers to default states QUEue Path to access error queue NEXT Read the most recent error message Note 4 ENABle list Specify error...

Страница 376: ...le autozero ON STATe Query autozero LSYNc Path to control line synchronization Sec 3 STATe b Enable or disable line sync OFF STATe Query state of line sync LFRequency Query power line frequency Sec 1...

Страница 377: ...annel Path to query isolated channels3 STARt Request lowest numbered isolated channel 0 isolated channels not supported END Request highest numbered isolated channel 0 isolated channels not supported...

Страница 378: ...LOCal Take Model 2790 out of remote and restore opera tion of front panel controls RS 232 only Sec 10 REMote Place Model 2790 in remote RS 232 only Sec 10 RWLock Lockout front panel controls RS 232 on...

Страница 379: ...an TRACe POINts value 50 NOTify Query trace notify value NEXT Query buffer location for next stored reading TSTamp Path to set timestamp format FORMat name Select timestamp format ABSolute or DELTa AB...

Страница 380: ...easure count DELay n Set delay 0 to 999999 999 sec 0 AUTO b Enable or disable auto delay OFF AUTO Query state of delay DELay Query delay SOURce name Select control source IMMediate TIMer MANual BUS or...

Страница 381: ...surement units V or DB V DB Path to set DB reference voltage REFerence n Specify reference in volts 1e 7 to 1000 1 REFerence Query reference DC clist Query DCV units AC name clist Select ACV measureme...

Страница 382: ...es how the reading limits are calculated Performing the verification test procedures Outlines the type of tests and summarizes test considerations Model 2790 verification Provides all the procedures n...

Страница 383: ...sentative or the factory to determine the correct course of action If the unit is not under warranty and it fails to meet specified limits refer to the calibration procedures in Section 17 There are t...

Страница 384: ...internal temperature to stabilize Typically allow one extra hour to stabilize a unit that is 10 C 18 F outside the specified temperature range Also allow the test equipment to warm up for the minimum...

Страница 385: ...5ppm 100V 7ppm 1000V 9ppm 100mV 200ppm 1 0V 82ppm 10V 82ppm 100V 90ppm 700V 85ppm 20mA 60ppm 100mA 70ppm 1A 110ppm 2 2A 94ppm 1A 690ppm 2 2A 682ppm 10 28ppm 19 26ppm 100 17ppm 1k 12ppm 10k 11ppm 100k...

Страница 386: ...mits 9 99965V to 10 00035V Calculating resistance reading limits Resistance reading limits must be recalculated based on the actual calibration resistance values supplied by the equipment manufacturer...

Страница 387: ...tiplexer Card Model 7751 7752 7753 verification use this procedure to verify accuracy of the sources of the Model 7751 7752 7753 cards Model 2790 tests Model 2790 verification test procedures include...

Страница 388: ...ollowing safety precautions when performing these tests Some of the procedures in this section may expose you to danger ous voltages Use standard safety precautions when such danger ous voltages are e...

Страница 389: ...PUTS switch is set to the FRONT position klqb Use shielded low thermal connections when testing the 100mV and 1V ranges to avoid errors caused by noise or thermal effects Connect the shield to the cal...

Страница 390: ...verification tests 5 Source positive and negative and full scale voltages for each of the ranges listed in Table 16 2 For each voltage setting be sure that the reading is within stated limits Table 16...

Страница 391: ...I and INPUT LO or 8 107 V Hz input because instrument damage may occur Follow these steps to verify AC voltage accuracy 1 Connect the Model 2790 HI and LO INPUT jacks to the AC voltage calibrator as s...

Страница 392: ...f the 5725A amplifier is not available change the 700V 50kHz step to 220V 50kHz Reading limits for 220V 50kHz 219 36 to 220 64V F F Model 2790 SourceMeter Switch System RANGE F 500V PEAK FRONT REAR 3A...

Страница 393: ...rrent verification Table 16 4 DCI limits DCI range Applied DC current Reading limits 1 year 18 C to 28 C 20mA 100mA 1A 3A 20 0000mA 100 0000mA 1 000000A 3 000000A 19 9892 to 20 01080mA 99 9100 to 100...

Страница 394: ...e AC currents as summarized in Table 16 5 and verify that the readings are within stated limits Table 16 5 ACI limits ACI range Applied AC current Reading limits 1kHz 1 year 18 C to 28 C 1A 3A 1 00000...

Страница 395: ...with the RATE key 4 Set the Model 2790 for the 100 range and make sure the FILTER is on Enable OCOMP offset compensated ohms by pressing SHIFT then OCOMP Use OCOMP for 100 range verification 5 Recalc...

Страница 396: ...to __________ k __________ to __________ k __________ to __________ M __________ to __________ M __________ to __________ M Enable O COMP offset compensated ohms when testing 100 range Calculate limi...

Страница 397: ...S switch is in the FRONT position 2 Configure the Model 2790 temperature function for C units and RTD temperature sensor 0 00385 as follows a Press SHIFT then SENSOR Note the unit displays the tempera...

Страница 398: ...790 frequency reading is between 999 9Hz and 1 0001kHz Figure 16 7 Connections for Model 2790 frequency verification F F Model 2790 SourceMeter Switch System RANGE F 500V PEAK FRONT REAR 3A 250V AMPS...

Страница 399: ...o verify DC voltage accuracy 1 Connect the Model 7702 CH1 H and L INPUT terminals to the DC voltage calibra tor as shown in Figure 16 8 klqb Use shielded low thermal connections when testing the 100mV...

Страница 400: ...the DC volts verification tests 6 Source positive negative and full scale voltages for each of the ranges listed in Table 16 8 For each voltage setting be sure that the reading is within stated limit...

Страница 401: ...y 1 Connect the Model 7702 CH1 H and L INPUT terminals to the AC voltage calibrator as shown in Figure 16 9 Figure 16 9 Connections for Model 7702 AC volts verification 2 Install the Model 7702 in Slo...

Страница 402: ...o the calibrator as shown in Figure 16 10 Figure 16 10 Connections for Model 7702 DC current verification Table 16 9 Model 7702 ACV reading limits ACV range Applied AC voltage 1kHz reading limits 1 ye...

Страница 403: ...1 5 Source positive and negative full scale currents for each of the ranges listed in Table 16 10 and verify that the readings for each range are within stated limits 6 Press the OPEN key to open Chan...

Страница 404: ...o warm up for two hours before proceeding Be sure the front panel INPUTS switch is set to the REAR position 3 Select the AC current function by pressing the ACI key 4 Set the Model 2790 for the 1A ran...

Страница 405: ...resistance verification 100 to 10M ranges 2 Install the Model 7702 in Slot 1 of the Model 2790 then turn on the power and allow the unit to warm up for two hours before proceeding Be sure the front p...

Страница 406: ...resistance verification Range Nominal resistance Nominal reading limits 1 year 18 C to 28 C Recalculated limits 100 1k 10k 100k 1M 10M 100M 100 1k 10k 100k 1M 10M 100M 99 9880 to 100 0120 0 999894 to...

Страница 407: ...the front panel INPUTS switch is set to the REAR position 3 Select the temperature function by pressing the TEMP key Close Channel 1 by pressing the CLOSE key and keying in 101 4 Configure the Model 2...

Страница 408: ...the unit to warm up for two hours before proceeding Be sure the front panel INPUTS switch is set to the REAR position 3 Set the function generator to output a 1kHz 1V RMS sine wave 4 Select the Model...

Страница 409: ...lect the Model 2790 DCV function and the 1V range Close Channel 1 by pressing the CLOSE key and keying in 101 4 Select the Model 2790 RATIO function press SHIFT then RATIO 5 Set the calibrator output...

Страница 410: ...njury due to electrical shock Table 16 14 Recommended equipment for Model 7751 7752 7753 verification Keithley Model 2001 Digital Multimeter 1 500V 47ppm HP3458A Digital Multimeter 50mA 35ppm Fluke 57...

Страница 411: ...DMM DC amps function and enable autorange 4 Set the Model 7751 7752 7753 source current to 50mA as follows a Press SHIFT CARD then CONFIG b Select SLOT1 7751 SLOT1 7752 or SLOT1 7753 then press ENTER...

Страница 412: ...ss SHIFT CARD then CONFIG b Select SLOT1 7751 or SLOT1 7753 then press ENTER c Select the V C submenu then set the source to 500V d Press EXIT to return to normal display 5 Verify that the DMM reading...

Страница 413: ...to the REAR position 3 Select the Model 2790 DC volts function and enable autorange 4 Set calibrator output current to 50 A 7751 or 500 A 7753 and turn on its output 5 Using the CLOSE key close channe...

Страница 414: ...gure 16 19 2 Install the Model 7751 7752 7753 in Slot 1 of the Model 2790 then turn on the power and allow the unit to warm up for two hours before proceeding Be sure the front panel INPUTS switch is...

Страница 415: ...ce value 7 Verify that the resistance reading is within the limits calculated in step 6 8 Repeat steps 1 through 7 for the 20mA 10mA and 1mA source currents as shown in Table 16 15 using the indicated...

Страница 416: ...ble 16 16 7751 or Table 16 17 7753 for resistance values 2 Install the Model 7751 7753 in Slot 1 of the Model 2790 then turn on the power and allow the unit to warm up for two hours before proceeding...

Страница 417: ...16 17 7753 based on the actual characterized resistance value 7 Verify that the resistance reading is within the limits calculated in step 6 8 Repeat steps 1 through 7 for the remaining resistances a...

Страница 418: ...0V 50V 50V 50V 1G 100M 10M 100M 10M 1M 0 92282 to 1 07717G 98 186 to 101 814M 9 8585to 10 1415M 88 541 to 111 459M 9 4048 to 10 5952M 0 94747 to 1 05253M __________ to __________ __________ to _______...

Страница 419: ...16 38 Model 2790 SourceMeter Switch System Reference Manual...

Страница 420: ...ck calibration both from the front panel and via remote using the calibration code Comprehensive calibration Covers all the calibration steps necessary to calibrate all Model 2790 functions Manufactur...

Страница 421: ...r over the IEEE 488 bus or the RS 232 port DC only and AC only calibration may be performed individually if desired Environmental conditions Conduct the calibration procedures in a location that has A...

Страница 422: ...tests Some of the procedures in this section may expose you to dangerous voltages Use standard safety precautions when such dangerous voltages are encountered to avoid personal injury or death caused...

Страница 423: ...ry default code is 002790 Use the left and right arrow keys to move among the digits use the up range key to increment numbers and press the down range key to specify alphabetic letters Confirm the co...

Страница 424: ...AC only calibration procedures You can use alternate equipment such as a DC transfer standard and characterized resistors as long as that equipment has specifications equal to or better than those li...

Страница 425: ...calibration DC voltage calibration Resistance calibration DC current calibration AC voltage calibration AC current calibration Setting calibration dates Preparing the Model 2790 for calibration 1 Turn...

Страница 426: ...erminals Keep drafts away from low thermal connections to avoid thermal drift which could affect calibration accuracy 2 Press ENTER to start short circuit calibration While the unit is calibrating it...

Страница 427: ...sense leads are connected and dis connected at various points in this procedure by turning calibrator external sense on or off as appropriate If your calibrator does not have provisions for turning e...

Страница 428: ...ey to calibrate that step Wait until the Model 2790 finishes each step The unit will display the CALIBRATING message while calibrating klqb If your calibrator cannot output the values recommended in T...

Страница 429: ...ator cannot output the exact resistance value use the Model 2790 left and right arrow keys and the range keys to adjust the Model 2790 display to agree with the actual calibrator resistance Press the...

Страница 430: ...e 17 5 DC current calibration summary Calibration step Calibrator current Allowable range 10mA 100mA 1A 10 00000mA 100 0000mA 1 000000A 9mA to 11mA 90mA to 110mA 0 9A to 1 1A F F Model 2790 SourceMete...

Страница 431: ...at 1kHz 100mV AC at 1kHz 100mV AC at 50kHz 1V AC at 1kHz 1V AC at 50kHz 10V AC at 1kHz 10V AC at 50kHz 100V AC at 1kHz 100V AC at 50kHz 700V AC at 1kHz 10 00000mV 1kHz 100 0000mV 1kHz 100 0000mV 50kHz...

Страница 432: ...er the calibration date and the calibration due date Set these dates as follows 1 At the CAL DATE prompt use the left and right arrow keys and the range keys to set the calibration date then press ENT...

Страница 433: ...e calibration DC current calibration AC volts calibration AC current calibration Programming calibration dates Saving calibration constants Locking out calibration klqb As with front panel calibration...

Страница 434: ...tton is not pressed in so that the front inputs are active Wait at least three minutes before proceeding to allow for thermal equilibrium klqb Be sure to connect the low thermal short properly to the...

Страница 435: ...ration steps summarized in Table 17 8 For each step Set the calibrator to the indicated voltage and make sure the unit is in operate Use the recommended voltage if possible Send the indicated programm...

Страница 436: ...d make sure the unit is in operate Use the recommended resistance or the closest available value Send the indicated programming command Change the command parameter if you are using a different calibr...

Страница 437: ...orming DC only calibration proceed to Programming calibra tion dates AC voltage calibration Follow these steps for AC voltage calibration 1 Connect the calibrator to the Model 2790 INPUT HI and LO ter...

Страница 438: ...on step Calibrator voltage frequency Calibration command 10mV AC at 1kHz 100mV AC at 1kHz 100mV AC at 50kHz 1VAC at 1kHz 1VAC at 50kHz 10VAC at 1kHz 10VAC at 50kHz 100VAC at 1kHz 100VAC at 50kHz 700VA...

Страница 439: ...command is sent Locking out calibration After saving calibration send the following command to lock out calibration CAL PROT LOCK Manufacturing calibration The manufacturing calibration procedure is...

Страница 440: ...Extender Test Board should then be installed in scanner Slot 1 Test equipment connections Connections for steps requiring the calibrator are shown in Figure 17 5 and Figure 17 6 shows function generat...

Страница 441: ...E INPUTS 350V PEAK 1000V PEAK AUTO SHIFT LOCAL POWER RANGE R EXIT ENTER DIGITS RATE REL FILTER TRIG EX TRIG STORE RECALL OPEN DCV DCI MATH OUTPUT RATIO ACV ACI 2 4 FREQ TEMP CH AVG CONT PERIOD SENSOR...

Страница 442: ...ror is reported after performing this step refer to Table 17 14 for troubleshooting Frequency cal Connect the function generator to the front panel INPUT jacks Figure 17 6 Set the generator to output...

Страница 443: ...TEP15 1E3 11 Send the following commands to set calibration dates save calibration and lock out calibration CAL PROT DATE yyyy mm dd CAL PROT NDUE yyyy mm dd CAL PROT SAVE CAL PROT LOCK Calibration fo...

Страница 444: ...al Set the function generator to output a 1V RMS 1kHz sine wave Enter 1 000000kHz at the prompt then press ENTER 9 Set the calibration dates then save calibration to complete the process Remote manufa...

Страница 445: ...d 7753 modules the maximum common mode voltage voltage between any module terminal and chassis ground is 42V Exceeding this value may cause a breakdown in insulation creating a shock hazard klqb The s...

Страница 446: ...arm up period before proceeding 5 Enable calibration by sending the CODE command For example the default command is CAL PROT CODE KI002790 6 Initiate calibration by sending the following command CAL P...

Страница 447: ...NSE SRC HI SRC HI HI SRC HI SRC SRC LO SRC LO LO SRC LO SRC SEN HI SEN HI HI SEN HI SEN SEN LO SEN LO LO SEN LO SEN A A A A LO I V GUARD ISOURCE VSOURCE INTERLOCK OUT HI GND GND HI IN LO LO BANK 1 BAN...

Страница 448: ...amps fuses Discusses the method for replacing the two fuses that protect the Model 7702 current inputs Replacing Model 7751 7752 7753 plug in module fuses Discusses the method for replacing the four...

Страница 449: ...ement perform the following steps 1 Place the tip of a flat blade screwdriver into the power module by the fuse holder assembly see Figure 18 1 Gently push in and to the left Release pressure on the a...

Страница 450: ...200 240V 1 4A 250V 5 20 mm slow blow FU 96 4 KEITHLEY SLOT COVER DIGITAL I O TRIG LINK RS232 WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY CAUTION FOR CONTINUED PRO...

Страница 451: ...e it with the same type 3A 250V fast blow Keithley part number FU 99 1 rqflk Do not use a fuse with a higher current rating than specified or instru ment damage may occur If the instrument repeatedly...

Страница 452: ...o so Make sure that all plug in module connections are de energized and disconnected before replacing module amps fuses 1 Turn off the power and disconnect external connections from the Model 7702 2 O...

Страница 453: ...g in module fuses t okfkd The information in this section is intended only for qualified service personnel Do not perform these procedures unless you are qualified to do so Make sure that all plug in...

Страница 454: ...cuit board with a foam tipped swab or brush dipped in pure water then blow dry the board with dry nitrogen gas Allow the board to dry for several hours in a 50 C low humidity environment before use 9...

Страница 455: ...ded only for qualified service person nel Do not perform this procedure unless you are qualified to do so Disconnect the line cord and all connecting wires from the Model 2790 before removing the top...

Страница 456: ...before use 7 Re install the top cover Plug in module relay closure count The Model 2790 keeps an internal count of the number of times each module relay has been closed This count will help you deter...

Страница 457: ...relay closure count klqb The Model 2790 must be in the manufacturing calibration mode to reset the closure count To do so press and hold the OPEN key while turning on the power then send the CAL PROT...

Страница 458: ...ften may reduce scanning throughput The higher the interval the less scanning throughput is reduced but more relay counts may be lost in the event of a power failure To set the count update interval s...

Страница 459: ...SP 3 Press ENTER to start the test There are five parts to the display test Each time ENTER is pressed the next part of the test sequence is selected The five parts of the test sequence are as follows...

Страница 460: ...SourceMeter Switch System including the specifications for the Models 7751 7752 and 7753 modules Ohms specification calculations 7751 7752 7753 Provides equations to calculate ohms specifications for...

Страница 461: ...A 2 Specifications Model 2790 SourceMeter Switch System Reference Manual...

Страница 462: ...Model 2790 SourceMeter Switch System Reference Manual Specifications A 3...

Страница 463: ...A 4 Specifications Model 2790 SourceMeter Switch System Reference Manual...

Страница 464: ...Model 2790 SourceMeter Switch System Reference Manual Specifications A 5...

Страница 465: ...A 6 Specifications Model 2790 SourceMeter Switch System Reference Manual...

Страница 466: ...Model 2790 SourceMeter Switch System Reference Manual Specifications A 7...

Страница 467: ...ent of reading plus an ohms offset 7751 7752 7753 I source Low ohms specifications using the I source of the 7751 7752 7753 are provided for the following current output settings 50mA 20mA 10mA and 1m...

Страница 468: ...e temperature coefficient for an I source setting of 30mA of reading 0 001 0 025 30 C 0 001 0 00083 0 00183 C Ohms offset 0 001 30 C 0 033m C Ohms temperature coefficient 30mA 0 00183 0 033m C 7751 77...

Страница 469: ...ltage source settings Figure A 2 Model 7753 measurement uncertainty for various voltage source settings 0 1 1 0 10 0 Resistance Under Test Uncertainty 50 100 200V 500V 300V 400V Voltage Source Setting...

Страница 470: ...C For measurements 10M to 100M TC of reading 0 02 6 VSOURCE C TC ohms offset 200 C where VSOURCE is the voltage output setting in volts Example Determine temperature coefficient for a V source settin...

Страница 471: ...A 12 Specifications Model 2790 SourceMeter Switch System Reference Manual...

Страница 472: ...B StatusandErrorMessages...

Страница 473: ...ram currently running Illegal program name Cannot create program Expression error Hardware missing Data corrupt or stale Out of memory Illegal parameter value Too much data Parameter data out of range...

Страница 474: ...ny digits Exponent too large Invalid character in number Numeric data error Header suffix out of range Undefined header Program mnemonic too long Header separator error Command header error Missing pa...

Страница 475: ...running Waiting in trigger layer Re entering the idle layer Filter settled Reading overflow Low limit 1 event High limit 1 event Low limit 2 event High limit 2 event Reading available Buffer user sel...

Страница 476: ...k 4 w zero error 10k 4 w zero error 100k 4 w zero error 10M 4 w sense lo zero error 1k 4 w full scale error 10k 4 w full scale error 100k 4 w full scale error 1M 4 w full scale error 10M 4 w full scal...

Страница 477: ...or 1V 10Hz amplitude error Frequency gain error 1K Ohm loff Ocomp FS error 10K Ohm loff Ocomp FS error Temperature Cold Cal error Analog output zero error Analog output positive gain error Analog outp...

Страница 478: ...ard memory pattern mismatch Questionable calibration Questionable temperature Invalid function in chanlist Memory pattern full No measurement channel in scanlist RS 232 Framing error detected RS 232 O...

Страница 479: ...B 8 Model 2790 SourceMeter Switch System Reference Manual...

Страница 480: ...nal processing information instrument features and defines processing using Ratio or Channel Average Data flow remote operation Defines data flow for remote operation Defines specific commands Provide...

Страница 481: ...2790 Based on the selected measurement function and range signal conditioning transforms the input signal into a DC voltage that is applied to the A D converter The A D Conversion Process measures th...

Страница 482: ...through to the next enabled feature or to the display Figure C 2 Signal processing using instrument features Input Signal Rel Math mX b m X b Percent SxIohms or SxVohms Rel ed reading Reading Rel valu...

Страница 483: ...of readings to be averaged In general for the moving filter each measurement process adds a reading to the stack oldest reading discarded and then averages the stack to yield a filtered reading For th...

Страница 484: ...fied and is the reading that is displayed on the Model 2790 With Limits enabled the reading is tested against two sets of high and low limits Along with the displayed reading annunciators and messages...

Страница 485: ...s and that reading is used as the Chan B value for the calcu lation Ratio or Ch Avg is then calculated as shown in Figure C 3 As shown the result of Ratio or Ch Avg can then be used by an enabled Math...

Страница 486: ...or this triggering configura tion is summarized by the block diagram shown in Figure C 4 Refer to this block diagram for the following discussion Figure C 4 Data flow for remote operation SENSe Measur...

Страница 487: ...disables continuous initiation and TRIGger COUNt 1 configures the instrument to perform one measurement cycle The INIT command can then be used to initiate the measurement cycle When the INIT command...

Страница 488: ...arrays Reading numbers that do not change will indicate that the same data array is being returned klqb The FORMat ELEMents command see Section 14 is used to include the reading number RNUM element i...

Страница 489: ...te that FETCh does not affect data in the sample buffer Therefore subsequent execu tions of FETCh acquire the same data klqb When an instrument setting that is relevant to the readings in the sample b...

Страница 490: ...do not affect data in the sample buffer Therefore subsequent executions of these commands return the same data With no math function enabled these commands return the last data array stored in the sam...

Страница 491: ...be returned when a read operation CALC2 IMM or CALC2 DATA is performed However if there was no calculation previously performed the number 9 910000E 37 will instead be returned Continuous measurement...

Страница 492: ...Once the scan is properly configured INIT or READ will start the scan READ also returns the scanned readings data arrays from the sample buffer or the CALC1 block if Math is enabled FETCh will not st...

Страница 493: ...C 14 Model 2790 SourceMeter Switch System Reference Manaul...

Страница 494: ...rement considerations Provides information on thermoelectric poten tials thermoelectric generation minimizing thermal EMFs source resistance noise magnetic fields radio frequency interference ground l...

Страница 495: ...w Level Measurements handbook which is available from Keithley Thermoelectric potentials Thermoelectric potentials thermal EMFs are small electric potentials generated by differences in temperature at...

Страница 496: ...B junction C or K T2 Temperature of A junction C or K In the unlikely event that the two junction temperatures are identical no thermal EMFs will be generated More often the two junction temperatures...

Страница 497: ...e the connection is gas tight to prevent future oxidation In some cases connecting the two thermal junctions together with good thermal contact to a common heat sink may be required Unfortunately most...

Страница 498: ...ance of 10k the noise over a 0 5Hz bandwidth at room temperature will be Minimizing source resistance noise From the above examples it is obvious that noise can be reduced in several ways 1 lower the...

Страница 499: ...s Radio frequency interference RFI Radio Frequency Interference is a general term used to describe electromagnetic interference over a wide range of frequencies across the spectrum Such RFI can be par...

Страница 500: ...urn path such as power line ground As shown in Figure D 2 the resulting ground loop causes current to flow through the instrument LO signal leads and then back through power line ground This circulati...

Страница 501: ...is connected to power line ground Ground loops are not normally a problem with instruments like the Model 2790 that have isolated LO terminals However all instruments in the test setup may not be des...

Страница 502: ...level measurement situation Otherwise interference from such noise sources as line frequency and RF fields can seriously corrupt measure ments rendering experimental data virtually useless In order t...

Страница 503: ...the input resistance of the Model 2790 is RI and the voltage measured by the nanovoltmeter is VM Figure D 5 Meter loading The voltage actually measured by the meter is attenuated by the voltage divide...

Страница 504: ...ocuments the Steinhart Hart equation which is used to calculate thermistor temperature RTD equation Documents the Callendar Van Dusen equation which is used to calculate the temperature vs resistance...

Страница 505: ...stor temperature measurement accuracy of the Model 2790 see Appendix A is based on the curve fitting constants listed in Table E 1 If the thermistor manufacturer s curve fitting constants are not exac...

Страница 506: ...re T C is the temperature in C TK is the calculated Kelvin temperature Example Calculate the temperature for a Series 44007 thermistor that measures 5k R lnR ln 5000 8 5172 A 0 001288 B 0 0002356 C 9...

Страница 507: ...stance of a PT100 RTD at 100 C T The following R0 at 0 C alpha beta and delta values are used for the PT100 RTD Table E 2 T 100 C R0 at 0 C 100 alpha 0 003850 beta 0 10863 delta 1 49990 Using the abov...

Страница 508: ...Switch System Reference Manual E 5 The resistance of the RTD at 100 C R100 is then calculated as follows R100 R0 1 AT BT2 CT3 T 100 100 1 0 00391 100 5 77e 7 1002 4 18e 12 1003 100 100 100 1 0 391 0...

Страница 509: ...E 6 Model 2790 SourceMeter Switch System Reference Manual...

Страница 510: ...F IEEE 488BusOverview...

Страница 511: ...on transfer since the task of listening takes up bus time Through the use of control lines a handshake sequence takes place in the transfer process of information from a talker to a listener This hand...

Страница 512: ...truments on the bus The talker sends data while a listener receives data Depending on the type of instrument any particular device can be a talker only a listener only or both a talker and listener Fi...

Страница 513: ...n a similar manner the talk address is obtained by ORing the primary address with 40 With the present example the talk address derived from a primary address of 16 would be 56 56 16 40 The IEEE 488 st...

Страница 514: ...wo lines are controlled by accepting devices the listener or lis teners receiving the information The three handshake lines are DAV DATA VALID The source controls the state of the DAV line to indicate...

Страница 515: ...aphs Figure F 2 IEEE 488 handshake sequence Bus commands The instrument may be given a number of special bus commands through the IEEE 488 interface The following paragraphs briefly describe the purpo...

Страница 516: ...lengths to be transmitted easily IFC Interface Clear IFC is used to clear the interface and return all devices to the talker and listener idle states Table F 1 IEEE 488 bus command summary Command ty...

Страница 517: ...oller to remove all devices on the bus from the serial poll mode and is generally the last command in the serial polling sequence Addressed multiline commands Addressed commands are multiline commands...

Страница 518: ...UNL Unlisten Listeners are placed in the listener idle state by the UNL command UNT Untalk Any previously commanded talkers will be placed in the talker idle state by the UNT command Common commands C...

Страница 519: ...nes are summarized in Figure F 3 Hexadecimal and the decimal values for the various commands are listed in Table F 2 Table F 2 Hexadecimal and decimal command codes Command Hex value Decimal value GTL...

Страница 520: ...C1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US LLO DCL PPU SPE SPD 1 B 2 A SP _ 2 B 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 3 A 0 1 2 3 4 5 6 7 8 9 3 B 16 17 18 19 20 21 22 23 24 25 26 27 28 29 3...

Страница 521: ...sent Note that ATN is true for both the listen command and the SDC command byte itself Table F 4 gives a typical common command sequence In this instance ATN is true while the instrument is being addr...

Страница 522: ...ATA VALID UNIVERSAL COMMAND GROUP ATN ATTENTION DCL DEVICE CLEAR IFC INTERFACE CLEAR REN REMOTE ENABLE SPD SERIAL POLL DISABLE SPE SERIAL POLL ENABLE ADDRESS COMMAND GROUP LISTEN TALK LAG LISTEN ADDRE...

Страница 523: ...s T5 exist only after the instrument has been addressed to talk L Listener Function The ability for the instrument to receive device dependent data over the bus from other devices is provided by the L...

Страница 524: ...ialized DT Device Trigger Function DTI defines the ability of the Model 2790 to have readings triggered C Controller Function The instrument does not have controller capabilities C0 E Bus Driver Type...

Страница 525: ...F 16 Model 2790 SourceMeter Switch System Reference Manual...

Страница 526: ...G CalibrationReference...

Страница 527: ...this subsystem are protected by the calibration lock except queries and CODE CODE up to 8 char string Calibration code or password default KI002790 COUNt Request the number of times the unit has been...

Страница 528: ...AC at 1kHz step STEP7 10V AC at 50kHz step STEP8 100V AC at 1kHz step STEP9 100V AC at 50kHz step STEP10 700V AC at 1kHz step STEP11 100mA AC at 1kHz step STEP12 1A AC at 1kHz step STEP13 2A AC at 1kH...

Страница 529: ...t to the unit before sending any other comprehensive or manufacturing calibration command The default calibration code is KI002790 klqb The CODE command should be sent only once before performing eith...

Страница 530: ...ore performing either DC AC or factory calibration Do not send INIT before each calibration step Example CAL PROT INIT Initiate calibration LOCK CALibration PROTected LOCK Purpose To lock out comprehe...

Страница 531: ...K Request cal lock state SAVE CALibration PROTected SAVE Purpose To save calibration constants in EEROM after the calibration procedure Format cal prot save Parameters None Description The SAVE comman...

Страница 532: ...he CALIBRATION selection in the front panel CAL menu Example CAL PROT DATE 2002 3 16 Send cal date 3 16 2002 CAL PROT DATE Request cal date NDUE CALibration PROTected NDUE Purpose To send the next cal...

Страница 533: ...put jacks before sending this command Example CAL PROT DC STEP1 Perform short circuit calibration Table G 2 DC calibration commands Command Description Parameter limits CALibration PROTected DC STEP1...

Страница 534: ...hensive calibration step Format cal prot dc step3 Cal_voltage Parameters Cal_voltage 9 to 11 V Description STEP3 programs the 10V DC comprehensive calibration step The allowable range of the calibrati...

Страница 535: ...ormat cal prot dc step6 Cal_resistance Parameters Cal_resistance 0 9E3 to 1 1E3 Description STEP6 programs the 1k 4 wire resistance comprehensive calibration step The allowable range of the calibratio...

Страница 536: ...n step Format cal prot dc step9 Cal_resistance Parameters Cal_resistance 900E3 to 1 1E6 Description STEP9 programs the 1M comprehensive calibration step The allow able range of the calibration resista...

Страница 537: ...t parameter is from 90E 3 to 110E 3 Use the 100E 3 value whenever possible for best results Example CAL PROT DC STEP11 0 1 Program 100mA step STEP12 CALibration PROTected DC STEP12 Purpose To program...

Страница 538: ...10mV AC at 1kHz calibration step STEP2 100mV AC at 1kHz calibration step STEP3 100mV AC at 50kHz calibration step STEP4 1V AC at 1kHz calibration step STEP5 1V AC at 50kHz calibration step STEP6 10V A...

Страница 539: ...at 1kHz calibration step 7 10V AC at 50kHz calibration step 8 100V AC at 1kHz calibration step 9 100V AC at 50khz calibration step 10 700V AC at 1kHz calibration step 11 100mA AC at 1kHz calibration s...

Страница 540: ...n The AC STEP14 and AC STEP 15 commands program the two manufacturing AC calibration steps The appropriate signal must be connected to the instrument when programming each step as summa rized by the p...

Страница 541: ...queries and CODE CODE up to 8 char string Send calibration code Default KI002790 CARD1 Path to calibrate card in slot 1 INITiate Initiate card calibration COUNt Request number of times card in slot 1...

Страница 542: ...002790 klqbp The CODE command should be sent only once before performing calibration Do not send CODE before each calibration step The code parameter must be enclosed in single quotes Example CAL PROT...

Страница 543: ...klqb The card calibration date is automatically set to the Model 2790 real time clock date when the card is calibrated Example CAL PROT CARD1 DATE 1 Request card 1 cal date INIT CALibration PROTected...

Страница 544: ...Purpose To read Model 7751 7752 7753 calibration lock status Format cal prot card1 lock Response 0 Calibration locked 1 Calibration unlocked Description The LOCK query requests status from the Model 2...

Страница 545: ...ading should be recorded The Isource DAC will be set to 0 8 65536 or 52429 DATA NRf NRf sends the two readings from the DMM for the low and high points for the Isource readings The first parameter is...

Страница 546: ...nd stores calculated calibration constants derived during Model 7751 7752 7753 calibration in card EEROM EEROM is non volatile memory Calibration constants will be retained indefinitely once saved Gen...

Страница 547: ...r number Error message 400 10 vdc zero error 401 100 vdc zero error 402 10 vdc full scale error 403 10 vdc full scale error 404 100 vdc full scale error 405 100 vdc full scale error 406 1k 2 w zero er...

Страница 548: ...ero error 463 100 vac full scale error 464 750 vac zero error 465 750 vac full scale error 466 750 vac noise error 467 Post filter offset error 468 1 aac zero error 469 1 aac full scale error 470 3 aa...

Страница 549: ...send the following command SRE 4 This command will enable SRQ when the EAV bit is set You can then read the status byte and error queue as outlined above to check for errors and to determine the exac...

Страница 550: ...appear on the same line as the calibration command 3 After sending a calibration command repeatedly test the ESB Event Summary bit bit 5 in the status byte until it is set Use either the STB query or...

Страница 551: ...cables Keithley Model 7007 Software requirements In order to use the calibration program you will need the following software Microsoft QBasic supplied with MS DOS 5 0 or later MS DOS version 5 0 or l...

Страница 552: ...e Model 2790 is set for a primary address of 16 Use the front panel GPIB key to check or change the address 4 Make sure the calibrator primary address is at its factory default setting of 4 5 Make sur...

Страница 553: ...output C CAL PROT 2790 partial command header CLS Clear CRT PRINT Model 2790 Multimeter Comprehensive Calibration Program PRINT 1 OUTPUT 16 CAL PROT CODE KI002790 Send KI002790 cal code PRINT 1 OUTPUT...

Страница 554: ...6 CAL PROT SAVE Save calibration constants GOSUB ErrCheck PRINT 1 OUTPUT 16 CAL PROT LOCK Lock out calibration PRINT Calibration completed PRINT 1 OUTPUT 16 SYST PRES END KeyCheck Check for key press...

Страница 555: ...C STEP2 DATA OUT 10 V 0 HZ DC STEP3 10 DATA OUT 10 V DC STEP4 10 DATA OUT 100 V DC STEP5 100 DATA OUT 1 KOHM DC STEP6 DATA OUT 10 KOHM DC STEP7 DATA OUT 100 KOHM DC STEP8 DATA OUT 1 MOHM DC STEP9 DATA...

Страница 556: ...31 schematic 2 32 Switching module capabilities 2 31 A AC calibration commands G 13 AC current verifying Model 2790 16 13 AC voltage verifying Model 2790 16 10 verifying Model 7702 16 20 AC voltage of...

Страница 557: ...52 17 26 Model 7751 7752 17 27 preparing the Model 2790 17 6 recommended equipment 17 5 resistance 17 10 setting dates and saving 17 13 step completion G 24 calibration code front panel 17 4 remote 17...

Страница 558: ...OPT 12 5 RCL 12 6 RST 12 6 SAV 12 6 SRE 11 9 SRE 11 9 STB 11 9 TRG 12 7 TST 12 7 Common errors 3 11 Connections 2 wire system channel 2 8 4 wire RTDs 3 24 4 wire system channel 2 9 AC volts calibratio...

Страница 559: ...ming 5 23 Scanning 5 23 DC calibration commands G 8 DC current verifying Model 2790 16 12 verifying Model 7702 16 21 DC voltage Verifying Model 2790 16 8 verifying Model 7702 16 18 DCI and ACI connect...

Страница 560: ...nnel average programming examples 5 22 Read error queue 11 22 Rel programming examples 5 6 Scanning 7 33 Scanning programming example 7 33 Serial poll programming example 11 10 Set MSS B6 when error o...

Страница 561: ...d groups F 13 IEEE 488 Bus configuration F 3 Bus overview F 1 Connector 1 12 10 4 IEEE 488 2 common commands see Common commands IEEE 754 single precision format 14 4 Inputs Front panel 1 11 1 25 INPU...

Страница 562: ...quipment 17 21 remote 17 23 17 25 Unlocking manufacturing calibration 17 21 Math 5 7 Basic operation 5 14 Commands 5 15 mX b 5 8 5 9 Percent 5 11 Percent reference 5 16 Programming examples 5 17 Remot...

Страница 563: ...s 1 3 Output trigger 7 10 8 5 P Paired channels see 4 wire functions Percent math function 5 11 Configuration 5 11 Reference 5 16 Performance considerations 3 4 Plug in switching modules 1 3 1 6 Power...

Страница 564: ...us byte and service request SRQ Status byte register 11 7 Status register sets 11 2 11 12 Relative 5 2 Basic operation 5 2 commands 5 4 Pressing REL using rel commands 5 6 Programming examples 5 6 Rem...

Страница 565: ...uration 7 20 Basic scan 7 21 Buffer 7 22 Configuration 7 10 dB 5 23 Digital outputs 9 12 Digits 4 6 Examples 7 33 External trigger scan example 7 34 Filter 4 17 Fundamentals 7 2 Limits 9 4 Manual exte...

Страница 566: ...wire functions 2 7 4 wire functions paired channels 2 8 SYSTem commands 14 8 SYSTem BEEPer STATe b 14 9 SYSTem KEY NRf 14 8 SYSTem PRESet 14 8 SYSTem VERSion 14 8 T Temperature Best temperature senso...

Страница 567: ...2 16 28 Verification limits 16 5 Verification test considerations 16 7 Model 2790 16 6 Model 7702 16 6 summary 16 6 verification test procedures 16 6 Verification test requirements 16 2 verifying AC c...

Страница 568: ...ll other trademarks and trade names are the property of their respective companies A G R E A T E R M E A S U R E O F C O N F I D E N C E Keithley Instruments Inc Corporate Headquarters 28775 Aurora Ro...

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