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User’s Manual

Model SR715
Model SR720

LCR Meters

1290-D Reamwood Avenue

Sunnyvale, California 94089

Phone: (408) 744-9040  •  Fax: (408) 744-9049

email: [email protected]  •  www.thinkSRS.com

Copyright © 1991 by SRS, Inc.

All Rights Reserved.

Revision 1.5 (09/2001)

Summary of Contents for SR715

Page 1: ...R715 Model SR720 LCR Meters 1290 D Reamwood Avenue Sunnyvale California 94089 Phone 408 744 9040 Fax 408 744 9049 email infor thinkSRS com www thinkSRS com Copyright 1991 by SRS Inc All Rights Reserved Revision 1 5 09 2001 ...

Page 2: ...SMD Tweezers 2 14 BNC Adapter 2 15 Open Short Calibration 2 16 Suggestions for Calibration 2 16 Radial Fixture 2 16 Axial Fixture Adapter 2 16 Kelvin Clips 2 16 SMD Tweezers 2 17 Other Fixtures 2 17 Binning 2 18 Setting Up the Bins 2 19 Examples 2 20 Binning Worksheet 2 21 Option 01 GPIB Handler Interface 2 22 ACCURACY Conditions 3 1 Impedance Accuracy 3 2 R Q Accuracy 3 4 L Q Accuracy 3 5 C D Acc...

Page 3: ... Floating Point Calbytes 5 11 Amplitude Calibration 5 12 Frequency Calibration 5 13 Standard Resistor Calibration 5 13 TROUBLESHOOTING and MAINTENANCE Nothing Happens at Turn On 6 1 Reset 6 1 Internal Fuse 6 1 External Bias Fuse 6 1 Error Messages 6 2 Operations Errors 6 2 Self test Errors 6 2 Calibration Errors 6 4 GPIB Problems 6 4 RS232 Problems 6 4 Fixture Maintenance 6 5 Cleaning 6 5 Removing...

Page 4: ...against electrical shock Always use an outlet which has a properly connected protective ground BIAS VOLTAGE ON CAPACITORS Verify that polarized capacitors are installed with the correct polarity before applying a bias voltage Failure to do so can result in damage to the unit the device under test or possible injury The SR715 720 fixture and remote fixtures are marked with and signs or by red leads...

Page 5: ...SR715 720 LCR METER iv ...

Page 6: ...Circuit Series or Parallel Parameters Displayed Value Deviation Deviation or Bin Number Deviation and deviation are calculated from a stored relative value Averaging 2 10 Measurements Measurement Range R Q R 0 0001 Ω 2000 MΩ Q 0 00001 50 L Q L 0 0001 µH 99999 H Q 0 00001 50 C D C 0 0001 pF 99999 µF D 00001 10 C R C 0 0001 pF 99999 µF R 00001 99999 kΩ TEST CONDITIONS Test Frequency 100 Hz 120 Hz 1 ...

Page 7: ...apters for axial leaded parts Protection Protected up to 1 Joule of stored energy 200 VDC max for charged capacitors Fused at 0 25 A output current for biased measurement Zeroing Open and Short Circuit Compensation Compensation Limits Short R 20 Ω Z 50 Ω Open Z 10 kΩ Binning Up to 8 Pass Bins QDR and General Fail Bins all defined from the front panel or over the computer interfaces Binning setups ...

Page 8: ... lines are Open Collector and are rated to 40 volts The trigger input is negative edge triggered TTL and is protected to 15 Volts SR726 Kelvin Clips Provides connection to devices that are not easily accommodated in the fixture Polarity is indicated for biased measurements Connects to SR715 720 fixture SR727 SMD Tweezers Provides connection to Surface Mount Device parts Polarity is indicated for b...

Page 9: ...built in fixture for measuring radial leaded components like most capacitors and adapters for measuring axial leaded components like most resistors To measure a radial leaded component remove any adapters and put one lead of the component in each side of the fixture To measure an axial leaded component first install the fixture adapters Put the adapters on in the middle of each side of the fixture...

Page 10: ...in the performance of the capacitor The quality factor Q is the ratio of the imaginary impedance to the real impedance For inductors a high Q indicates a more reactively pure component A low Q indicates a nearly pure resistor Q varies with frequency Q is commonly used to describe inductors With resistors often all that is stated is that the resistor has low inductance The dissipation factor D is e...

Page 11: ...ps for Measuring Typical Parts Component Type Value Parameter Type Equivalent Circuit Frequency Unknown Any Auto series 1 kHz Resistors 1 kΩ R Q series 1 kHz 1 kΩ R Q series 100 or 120 Hz 10 µH L Q series 100 kHz 10 µH 1 mH L Q series 10 kHz 1 mH 1 H L Q series 1 kHz 1 H L Q series 100 or 120 Hz 10 pF C D parallel 10 kHz 10 pF 400 pF C D series or parallel 10 kHz 400 pF 1 µF C D series 1 kHz 1 µF ...

Page 12: ...through source resistance Rs which varies according to the measurement range The current flows to the virtual ground of A1 and through Rr the current conversion resistor The output of A1 provides a signal proportional to the current I x Rr The voltage across the DUT is measured with a separate signal path providing a 4 wire Kelvin connection The real and imaginary signals are obtained by multiplyi...

Page 13: ...e output format to verbose 0 or concise 1 ASCII or verbose 2 or concise 2 binary XALL Returns major and minor parameters plus bin number XBIN Returns bin number of current measurement XDLT Returns deviation between major parameter and nominal value XMAJ Returns value of the major parameter XMIN Returns value of the minor parameter XPCT Returns percent deviation between major parameter and nominal ...

Page 14: ...sed 2 Query Error Set on output queue overflow Too many responses waiting to be transmitted 3 unused 4 Execution err Set by an out of range parameter or non completion of some command due a condition such as an incorrect operating mode 5 Command err Set by a command syntax error or unrecognized command 6 URQ Set by any key press 7 PON Set by power on LCR bit name usage STATUS BYTE 0 Math Error Set...

Page 15: ...TING STARTED 1 1 SR715 720 LCR METERS This section of the manual provides an overall view of the SR715 720 For detailed operating information on specific features see the Operating and Programming sections ...

Page 16: ...ution The measured parameters L C or R and Q D or R are indicated by the LEDs above each numeric display If the AUTO LED is also on the unit is in the auto parameter mode The LED indicates that the measurement is displayed as a relative deviation from an entered nominal value Units are indicated by the LEDs located between the two displays Ω kΩ MΩ µH mH H pF nF or µF The minor parameter is dimensi...

Page 17: ... drive voltage is in the vernier mode The Cons Volt key places the unit in the constant voltage mode BIAS Internal selects a 2 0 VDC internal bias External selects an external bias source Pressing the active key Internal when internal bias is already selected or External when external is selected turns the bias off Note that the bias is used only for capacitance measurements Pressing either of the...

Page 18: ...e used when entering numeric parameters in the entry display such as nominal values of R C or L The Mž H µF key acts as a general purpose ENTER key for parameters with units not listed on any key such as percent This key is labeled on the panel above the key NUMERIC KEYS 0 9 The numeric keys enter parameters and are only active when the unit is in the entry display STORE and RECALL The unit can st...

Page 19: ...leaded components where the leads are on the same side are simply inserted into the test fixture one lead in each side Axial leaded devices leads at opposite ends require the use of the axial fixture adapters Surface mount SMD devices or components with large or unusually shaped leads can be measures with SMD tweezers or Kelvin Clips A BNC adapter is available for interfacing to remote fixtures If...

Page 20: ...2 interface The connector is configured as a DCE transmit on pin 3 receive Computer serial adapter which is usually a DTE use a straight thru serial cable See the programming section for more information SW1 These switches set baud rate parity and word length for the RS232 interface See the programming section for details on setting the interface HANDLER INTERFACE OPTION 01 This provides control l...

Page 21: ...inductance is either the equivalent series or parallel inductance of the device under test The units of inductance are µH mH or H Q is the ratio of the imaginary part of the impedance to the real part of the impedance Q is dimensionless and the same for both series and parallel representations If the major parameter inductance is negative then the part under test is capacitive C D Capacitance is s...

Page 22: ... value display shows the value of the component being measured The type of component is indicated by the LEDs above the display R Q L Q C D C R The units of each display are indicated by the unit LEDs to the right of the each display The AUTO LED indicates that the auto select parameter AUTO mode is active The Value display is enabled under all conditions DEV The DEV or deviation display shows the...

Page 23: ...e end of a measurement range or with low output signal levels The number of measurements to be averaged is set in the ENTRY display From the ENTRY display press the Average key The unit will display AvG in the left display and the present number of averages in the right display Set the desired number of averages 2 thru 10 and press the ENTER MΩ H µF key Return to the desired display type using the...

Page 24: ...ry and allow another value to be entered The Calibrate key is used to access a series of less often used functions They are vtESt vernier test voltage SEttL settling time nuLL cAL null or open and short circuit cal and SELF tESt self test To access these functions press the Calibrate key until the desired function appears A message will appear along with the present value of that parameter The new...

Page 25: ...es Normalized to 1 0 Volt DUT Impedance Volts R3 or CV R2 R1 R0 The graph above shows the voltage across the Device Under Test DUT vs the DUT impedance for the different measurement ranges The values are normalized to a 1 0 V output drive setting for different applied voltages simply scale the graph values by the applied voltage Note that the voltage applied to the DUT is nearly equal to the outpu...

Page 26: ...y AUTORANGING During normal operations the unit automatically changes to the most accurate range for the device under test When the unit measures an impedance that is out of its current range it goes up or down one range and makes another measurement If this measurement is within the current range it displays it If not it changes ranges if available and repeats this process There is built in hyste...

Page 27: ...e a more appropriate range for the measurement Measurement accuracy is reduced if a component is measured outside of its optimal range The accuracy of an out of range measurement is as follows for each factor of 2 outside of the nominal range the total error increases by the basic error For example if a part is 4 times greater than the nominal range 2 factors of 2 then the total error will be the ...

Page 28: ...e SR715 720 or possible injury The SR715 720 is protected internally against discharging capacitors with up to 1 Joule of stored energy C V2 2 The internal and external bias circuitry will work only if the unit is in the C D or C R mode Bias cannot be applied if the unit is in the R Q L Q or the AUTO mode The error message of biAS for c will appear if the bias key is pressed in the inappropriate m...

Page 29: ... the fixture For occasional use non production with small capacitors 500 µF and low bias voltages 20 VDC the SR715 720 can discharge the capacitor internally Press the External bias key to switch off the bias The capacitor will then discharge through the unit in the same manner as the internal bias Another solution for somewhat larger bias voltages and or capacitors is to connect a resistor across...

Page 30: ...eral simple commands and responses like setting the frequency or checking what range the unit is on can be returned in about 10 mS Longer responses like XALL can take as long as 2 seconds over RS232 If communications speed is critical the binary data format which reduces the number of bytes transferred can be used SETTLING TIME Occasionally it is advantageous to delay making a measurement after th...

Page 31: ...a setup press the Store key which will display the StorE message in the display Press the number of the stored setting 1 9 and the ENTER key Store 0 ENTER will give an error since setup 0 is the factory default setup Recall To recall a stored setting press the Recall key which will display rcL Press the number of the stored setting 1 9 and the ENTER key Recall 0 returns the default setup including...

Page 32: ...he fixture to catch any leads that might fall through the fixture For information on removing leads or general maintenance to the fixture in general refer to the Maintenance section RADIAL LEADED PARTS To measure parts with radial leads leads coming out the same side of the package first remove any adapters or parts from the fixture since they will interfere with making a Kelvin connection Next ma...

Page 33: ...e minimum length of the part and lead combined is 0 7 17 8mm See the diagrams below Lead diameter for either fixture configuration can vary from 0 008 20mm or 32 AWG up to 0 070 1 8mm or 13 AWG OPTIONAL FIXTURES ADAPTER The Kelvin Clips SMD Tweezers and BNC adapters all connect to the SR715 720 fixture using the same adapter To install the fixture adapter first remove any parts or adapters from th...

Page 34: ...d other subtle conditions can change stray impedances affecting measurement accuracy For measurements outside of these limits a test fixture is advised SMD TWEEZERS The SMD Tweezers provide a combination of test fixture and handling tweezers for measuring surface mount devices The tweezers make a Kelvin connection to devices up to 0 4 10 2mm wide and make it easier to measure and sort these small ...

Page 35: ...eezers The four coax cables are labeled Ih red the drive signal Il blue the drive signal Vh orange the sense connection and Vl purple the sense connection When connecting these cables to a device connect the two signals to one side of the device and the two signals to the other side The leads have the same polarity as the fixture when using DC bias signals The shields of the four cables should not...

Page 36: ... impedances will be cancelled out as completely as possible Also keep any objects away from the fixture that will not be present during measurements for example hands or pieces of metal To observe the effect your hand has on impedances place a small capacitor 10pF in the fixture and observe the change in measured capacitance as you move your hand closer to the fixture This is due to your hand dist...

Page 37: ... SMD device by connecting the two ends with copper tape or solder to create a short circuit When performing open circuit cal hold the tips about the same distance apart as they will be when measuring parts and keep your hands still Sometimes it is valuable to check the quality of the null calibration by measuring the part that was used to perform the null cal the shorting block If the residual err...

Page 38: ...ntial Pass Fail has only two bins good parts and everything else Overlapping or nested bins have one nominal value and are sorted in progressively larger bins 1 2 3 Sequential bins can have different nominal values each separated by a percentage 9 nom 95 nom 1 0 nom 1 05 nom with 5 limits or a single nominal value and asymmetrical limits 3 to 1 1 to 1 1 to 3 Limits are pairs and can be symmetrical...

Page 39: ...in that the unit is set to the correct parameter R Q L Q C D or C R Press the Bin key which will bring up the bin entry display and put the unit in the entry mode If any previous binning information needs to be cleared press the Bin key until the bin cLEAr message appears Press the ENTER key to clear all bin data and display cLEAr donE To enter new bin data or to edit old bin data if it wasn t pre...

Page 40: ...ter to enter sequential binning data with a single nominal value and different percentage limits instead of with different nominal values overlapping limits are always entered in that fashion so it isn t an issue for them It is advisable to check the nominal values and limits before making measurements to be certain that they haven t been modified The binning setup can be viewed in the same manner...

Page 41: ...minal value of component ______________________ Tolerance to be sorted to ______________________ Entered by _______________________________________ Type of binning Pass Fail Nested Sequential bin nom lim lim 0 1 2 3 4 5 6 7 8 xxxx xxxx 9 xxxx xxxx xxxx ...

Page 42: ... Previous bin data if any is still available b A negative going pulse on the START line will trigger a reading The BUSY line will go low and stay low until the measurement is completed c After measuring the SR720 715 determines the proper bin to place the component During this time the BDA Bin Data Available line is activated to prevent reading invalid data After the proper bin location has been s...

Page 43: ...nput START line is active low and requires a pulse width of at least 50ns to activate edge triggered 1N4148 diodes protect against voltages exceeding TTL levels Outputs are provided by 7406 inverting buffers which have open collector outputs and therefore need pull up resistors for proper operation NOTE Maximum High level output voltage 30 V Maximum Low level output current 40 mA Example When conn...

Page 44: ... ACCURACY EQUATIONS The accuracy of a measurement is a function of the basic accuracy at that frequency measurement rate the signal amplitude and where the impedance of the DUT is within the measurement range The basic accuracy can be determined from the impedance graph or from the individual parametric graphs Additional factors are determined by the measurement conditions and the impedance of the...

Page 45: ...low Ki Table Meas Rate Frequency Zm Ki slow med all 1 fast 100 Hz 1 kHz 6 25 Ω Zm 400 kΩ 3 fast all other 2 Kv Table Vout V rms Kv 1 0 0 55 1 Vout 0 5 0 3 0 5 Vout 0 25 0 15 0 25 Vout 0 10 0 11 Vout Note that Kv equals one for the primary drive voltages 1 0 0 5 and 0 25 Vrms Kh Kl Table Frequency Kl Kh 100 120 1k Hz 1 mΩ Zm Zm 2 GΩ 10 kHz 1 mΩ Zm Zm 1 5 GΩ 100 kHz 4 mΩ Zm Zm 50 MΩ Zm the impedance...

Page 46: ...ACCURACY 3 3 ...

Page 47: ...hat the accuracy of Q is specified as a magnitude NOT as a percent Ki Table Meas Rate Frequency Zm Ki slow med all 1 fast 100 Hz 1 kHz 6 25 Ω Zm 400 kΩ 3 fast all other 2 Zm the impedance resistance of the device being measured Kv Table Vout V rms Kv 1 0 055 1 Vout 0 5 0 3 0 5 Vout 0 25 0 15 0 25 Vout 0 10 0 11 Vout Note that Kv equals one for the primary drive voltages 1 0 0 5 and 0 25 Vrms Kh Kl...

Page 48: ...curacy of Q is specified as a magnitude NOT as a percent Ki Table Meas Rate Frequency Zm Ki slow med all 1 fast 100 Hz 1 kHz 6 25 Ω Zm 400 kΩ 3 fast all other 2 Zm 2πfL impedance of device Kv Table Vout V rms Kv 1 0 0 55 1 Vout 0 5 0 3 0 5 Vout 0 25 0 15 0 25 Vout 0 10 0 11 Vout Note that Kv equals one for the primary drive voltages 1 0 0 5 and 0 25 Vrms Kh Kl Table Frequency Kl Kh 100 120 Hz 1 µH...

Page 49: ...t the accuracy of D is specified as a magnitude NOT as a percent Ki Table Meas Rate Frequency Zm Ki slow med all 1 fast 100 Hz 1 kHz 6 25 Ω Zm 400 kΩ 3 fast all other 2 Zm 1 2πfC impedance of device Kv Table Vout V rms Kv 1 0 0 55 1 Vout 0 5 0 3 0 5 Vout 0 25 0 15 0 25 Vout 0 10 0 11 Vout Note that Kv equals one for the primary drive voltages 1 0 0 5 and 0 25 Vrms Kh Kl Table Frequency Kl Kh 100 1...

Page 50: ... appropriate Use the impedance accuracy graph and equation on page 4 2 to obtain an impedance accuracy The accuracy of C and R are calculated from the impedance accuracy as follows Accuracy of C Zac x 1 D Accuracy of R Zac x 1 1 D where Zac is the impedance accuracy If the unit is in the constant voltage CV mode or under internal or external bias double the basic accuracy for Z Ki Table Meas Rate ...

Page 51: ... Rm where Rm the resistance of the device being measured and Rl Rh are given below Frequency Zl Rl Zh Rh R3 R2 R1 R0 R3 R2 R1 R0 100 120 1k Hz 1 mΩ 0 02 Ω 2 Ω 4 Ω 400 kΩ 6 5 MΩ 100 MΩ 2 GΩ 10 kHz 1 mΩ 0 02 Ω 2 Ω 6 Ω 400 kΩ 6 5 MΩ 100 MΩ 1 5 GΩ 100 kHz 4 mΩ 0 03 Ω 4 Ω xxx 200 kΩ 3 MΩ 50 MΩ xxx Inductance Kl Ll Lm Kh Lh Lm where Lm the inductance of the device being measured and Ll Lh are given belo...

Page 52: ...te 0 0 0 300 1 0 0 600 0 1 0 1200 1 1 0 2400 0 0 1 4800 1 0 1 9600 0 1 1 19 2 k bit3 1 parity on 0 parity off bit4 1 even parity 0 odd parity bit5 1 8 data bits 0 7 data bits Note the SR715 720 must be set to 8 data bits if the binary data output formats are to be used FRONT PANEL LEDS To assist in programming the SR715 720 has 3 front panel status LEDs The ACT LED flashes whenever a character is ...

Page 53: ...tification query no parameters TRG lf Triggers a measurement no parameters FREQ 1 FREQ lf Sets frequency to 120Hz 1 then queries the frequency PROGRAMMING ERRORS The SR715 720 reports two types of errors that may occur during command execution command errors and execution errors Command errors are errors in the command syntax For example unrecognized commands illegal queries lack of terminators an...

Page 54: ...query returns the present bias status CIRC i The CIRC command sets the SR715 720 s equivalent circuit to series i 0 or parallel i 1 The CIRC query returns the equivalent circuit setting CONV i The CONV command sets constant voltage off i 0 or on i 1 The CONV query returns the constant voltage setting FREQ i The FREQ command sets the drive frequency to 100 Hz i 0 120 Hz i 1 1 kHz i 2 10 kHz i 3 or ...

Page 55: ...urn the results of the SR715 720 s measurements The results may be returned in either ASCII or binary format and may or may not return measurement status information OUTF i Set OUTF command sets the format for the X commands to Verbose ASCII i 0 Concise ASCII i 1 Verbose Binary i 2 or Concise Binary i 3 The verbose formats return both measurement value and status information while the concise form...

Page 56: ...2 0 The ASCII values and 0 23h and 30h are header information indicating IEEE binary block data output 3 status An encoded status byte The bit values are given by xxxx0000 Measurement Good No errors xxxx0001 Invalid measurement no measurement A D error xxxx0010 Measurement overloaded xxxx0100 Underrange The measurement value is below the nominal range of values for this measurement range xxxx1000 ...

Page 57: ...at set by the OUTF command XMAJ The XMAJ query returns the value of the major parameter The value is returned in the format set by the OUTF command XMIN The XMIN query returns the value of the minor parameter The value is returned in the format set by the OUTF command XPCT The XPCT query returns the percent deviation between the major parameter and the nominal value see the PREL command If the nom...

Page 58: ...he stored setting is corrupt or has never been stored an execution error will be generated RCL0 recalls the default setup RST The RST common command resets the SR715 720 to its default configurations SAV i The SAV command saves the current instrument settings as setting number i 1 9 WAI The WAI common command is a synchronization command that halts further command processing until all measurements...

Page 59: ...can destroy the calibration of the SR715 720 CAL i The CAL i common query initiates the SR715 720 s self calibration routines When the calibration is complete the status of the calibration is returned The parameter i determines which calibration will be performed If i 0 the Short Circuit calibration will be done If i 1 the Open Circuit calibration will be done And if i 2 the Standard Resistor cali...

Page 60: ...e and quadrature counts for the current measurement DIA i The DIA command disables i 0 and enables i 1 diagnostic mode measurements The DIA query returns the diagnostic mode status FRQ x The FRQ command sets the frequency correction factor to x ppm x is rounded to the nearest 0 1 ppm and must be less than 10000 ppm The FRQ query returns the current frequency correction factor GAN i The GAN command...

Page 61: ... registers is set A bit is unmasked by setting the corresponding bit in the corresponding enable register to 1 The Serial Poll Status bits are not cleared until the condition which set the bit is cleared Thus these bits give a constant summary of the unmasked or enabled status bits A service request will be generated whenever an unmasked bit in the Serial Poll register is set Note that service req...

Page 62: ... over the communications interfaces The bits in this register stay set once set and are cleared by reading them or by the CLS command LCR bit name usage STATUS BYTE 0 Math Error Set on a floating point error 1 A D Error Set when an A D conversion fails 2 Overload Set when the gain stage is overloaded 3 Underrange Set when a measurement is below the nominal range of values for the present range 4 O...

Page 63: ... GPIB drivers are configured use IBIC This terminal emulation program allows you to send commands to the SR715 720 directly from your computer s keyboard If you cannot talk to the SR715 720 via IBIC then your programs will not run Use the simple commands provided by National Instruments Use IBWRT and IBRD to write and read from the SR715 720 After you are familiar with these simple commands you ca...

Page 64: ...it for the capacitor to charge up here when measuring large capacitors ibwrt lcr STRT WAI XALL 15L take a measurement wait until finished and get back the data printf Capacitance uf Dissipation n ibrd lcr string 80L get return string from LCR string ibcnt 0 terminate received string sscanf string lf lf d cmeas dissp bin get C and Dissipation bin value not used printf 7 5e 7 5e n cmeas 1 e6 dissp a...

Page 65: ...strates the use of the SR720 s binary return format A measurement is taken and returned to the computer along with the type of reading R L Q etc and measurement status This program is written in Microsoft C version 5 1 The header file for the GPIB interface is ms c488 h supplied by Capitol Equipment Corp To compile this program use CL AL c Then link the resulting object file with GPIB OBJ supplied...

Page 66: ...tf Underrange error n break case 8 printf Overrange error n break case 15 printf Out of range error n break default break transfer major parameter bytes 4 to create a single precision FP number memcpy maj data 3 4 store four bytes as a floating point number now do the same for the minor parameter memcpy min data 8 4 printf s 7 4e s 7 5e n mmaj mtype maj mmin mtype min void InitGpib void initialize...

Page 67: ...use the send function in the CEC library StatCheck address void GetGpib int address get an answer from device at address char r_string 40 temp 80 sprintf r_string UNT UNL MLA TALK d address transmit status r_string make device a talker StatCheck address check status for ok strcpy temp init answer string to null receive status length temp receive answer StatCheck address check status for ok strcpy ...

Page 68: ... bins of tolerances between 0 1 and 0 8 and provide a table of results This program is written in Microsoft C version 5 1 The header file for the GPIB interface ms c488 h is supplied by CEC To compile this program use the command CL AL c prog c Then link the resulting object file with GPIB obj supplied by CEC Ansi sys must be installed in config sys for proper screen format include ms c488 h inclu...

Page 69: ...lue to the LCR and the screen sprintf string BNOM8 lf nom 8 TxGpib lcr string printf nQDR fail value 7 5lf n nom 8 GetSpace TxGpib lcr BING1 turn on binning Clear clear screen measurement cycle while 1 Printxy 2 0 0 Insert resistor into the LCR fixture q to quit n GetSpace Erase 2 1 printf Measuring n TxGpib lcr STRT WAI XALL start a measurement wait until finished query the results GetGpib lcr ge...

Page 70: ...int address char command transmit command to address char t_string 100 int result result sprintf t_string UNT UNL MTA LISTEN d DATA s 10 address command transmit status t_string can also use the send function in the CEC library void GetGpib int address get an answer from device at address char r_string 40 temp 80 sprintf r_string UNT UNL MLA TALK d address transmit status r_string make device a ta...

Page 71: ...arting at row requires ansi sys int i for i 0 i num i row Gotoxy row 0 putch 27 printf K void Printxy int x int y int n char msg print msg at x y erasing n chars first int i Gotoxy x y for i 0 i n i printf Gotoxy x y printf msg void Gotoxy int row int col place the cursor at row col requires ansi sys putch 27 printf d dH row col ...

Page 72: ...gger a measurement and read the results from the LCR 20 30 Open com1 port for 9600 baud 8 bits no parity no handshaking 40 OPEN com1 9600 n 8 2 cs ds cd AS 1 50 PRINT 1 clear out com port 60 70 reset LCR set to triggered mode read C and R brief ascii data 80 PRINT 1 RST MMOD1 PMOD4 OUTF1 90 100 PRINT Resistance ohms Capacitance uF 110 PRINT 1 STRT WAI take a reading wait til finished before procee...

Page 73: ...eries or equivalent 1 Front Panel Test Verifies the front panel display digits LED s and keypad 1 Turn on the unit while holding down the Display key A single segment in the third digit of the left display should be on 2 Press the DOWN ARROW key to light each segment seven total and the decimal for the third and fourth digits of the left display for a total of 16 segments Only one segment or decim...

Page 74: ... SR715 720 to 0 25 and 0 10 V and verify that the output is within 2 of nominal 5 Set the amplitude back to 1 0 V Change the SR715 720 and scope settings to verify that the output at 100 Hz 120 Hz 10 kHz and 100 kHz SR720 only is within 2 of nominal 4 Resistance Measurement This verifies that the SR715 720 operates and is able to measure a component in each of its ranges The readings obtained shou...

Page 75: ...lel 1 kHz 3 Install the 22 nF capacitor Verify that the unit reads within 1 10 SR720 or 1 25 SR715 Verify that D is below 0001 4 Set the unit to 100 Hz Verify that the capacitance reading is close to the value measured above and within the tolerance stated above Repeat for 120 Hz D values should be below 0001 5 Repeat for 10 kHz and 100 kHz SR720 only At 10 kHz the tolerance is 1 15 SR720 or 1 35 ...

Page 76: ...0 05 IET HACS A 4 1000p 1000pF 10µF Fixture to BNC Adapter SRS SR728 BNC to stacking banana plugs 4 Pomona 3073 Test Conditions Warm up time At least 30 minutes Temperature 23 C 5 C 1 Frequency Accuracy This test measures the accuracy of the different output frequencies They should be within 0 01 100 ppm of the nominal value 1 Set the SR715 720 to its default conditions Recall 0 ENTER Set the unit...

Page 77: ...is 0 05 the tolerance of the resistance standard is 0 02 and thus the total tolerance is 0 07 or 0 7 Ω So the range of acceptable values is 999 3 Ω to 1000 7 Ω If standards with different tolerances are used the acceptable limits will have to be adjusted Resistance Accuracy 1 Connect the SR728 Fixture Adapter to the SR715 720 Install a BNC to stacking banana plug adapter on the end of each BNC cab...

Page 78: ...Connect the SR728 Fixture Adapter to the SR715 720 Install a BNC to stacking banana plug adapter on the end of each BNC cable Tape over or cut off the ground leads of the plugs connected to the orange Vh and purple Vl cables Connect the ground leads of the red Ih and blue Il cables to the case ground of the decade box Plug the orange and purple signal leads to the and terminals on the decade box P...

Page 79: ...10 kHz 2 9 9680n 10 032n 9 9880n 10 012n 10 0n 100 kHz 2 9 9780n 10 022n 100n 100 Hz 1 99 780n 100 22n 99 930n 100 07n 100n 1 kHz 2 99 780n 100 22n 99 930n 100 07n 100n 10 kHz 2 99 680n 100 32n 99 880n 100 12n 100n 100 kHz 3 99 780n 100 22n 1 000µ 100 Hz 2 99780µ 1 0022µ 99930µ 1 0007µ 1 000µ 1 kHz 2 99780µ 1 0022µ 99930µ 1 0007µ 1 000µ 10 kHz 3 99680µ 1 0032µ 99880µ 1 0012µ 10 000µ 100 Hz 2 9 978...

Page 80: ...___ Capacitance Test ____ ____ Frequency Accuracy Test Frequency Minimum Actual Maximum 100 Hz 99 99 Hz ________ 100 01 Hz 120 Hz 119 99 Hz ________ 120 01 Hz 1 kHz 999 90 Hz ________ 1000 1 Hz 10 kHz 9999 0 Hz ________ 10001 0 Hz 100 kHz 99990 0 Hz ________ 100010 0 Hz Amplitude Accuracy Amplitude Frequency Minimum Actual Maximum 1 0 Vrms 1 kHz 0 98 Vrms ________ 1 02 Vrms 1 0 Vrms 100 Hz 0 98 Vr...

Page 81: ...rallel ____________ ____ ____ 25 0000k 0 1 kHz parallel ____________ ____ ____ 100 0000k 0 1 kHz parallel ____________ ____ ____ 100 0000k 0 10 kHz parallel ____________ ____ ____ 400 0000k 0 1 kHz parallel ____________ ____ ____ if the Q value is greater than 0 1 the allowed tolerance must be multiplied by 1 Q Capacitance Accuracy capacitance Frequency Range Value Pass Fail 1 0n 1 kHz 0 _________...

Page 82: ...ving its four retaining screws this will break the calibration seal In the rear center of the circuit board is a three pin jumper labelled JP1001 Use the jumper to connect the center pin and the cal pin to enable calibration Connecting the center pin and the normal pin will disable calibration Calbytes The SR715 720 s calibration is controlled by calibration constants calbytes that the firmware us...

Page 83: ...48 49 0 60V 50 51 52 53 54 0 65V 55 56 57 58 59 0 70V 60 61 62 63 64 0 75V 65 66 67 68 69 0 80V 70 71 72 73 74 0 85V 75 76 77 78 79 0 90V 80 81 82 83 84 0 95V 85 86 87 88 89 1 00V 90 91 92 93 94 Floating Point Floating Point Calbyte Numbers 0 thru 120 Calbytes Number Name Meaning 0 Frequency Correction deviation from nominal in ppm 1 40 Reference Resistor Values impedance values organized in real ...

Page 84: ...eric entry keys 1 Connect the AC DC volt meter across the two sides of the fixture A small piece of wire inserted in each side of the fixture is a convenient way to connect the DVM Do not connect either end to ground Set the meter to AC volts autoranging Set the SR715 720 to its default conditions Recall 0 ENTER Set the unit to constant voltage mode 2 Set the amplitude and frequency for amplitude ...

Page 85: ...ocedure measures the value of the SR715 720 clock The exact clock frequency is used in calculating capacitance and inductance values The clock correction factor is stored in parts per million ppm 1 Set the SR715 720 to its default conditions Recall 0 ENTER Set the unit to constant voltage mode 1 kHz and remove any part from the fixture 2 Install the SR728 BNC adapter to the fixture Connect the Ih ...

Page 86: ... order begin calibration of the current range recall the factory default values or exit the cal menu 1 Inspect the fixture contacts for dirt or waxy build up If the fixture appears dirty clean it as described in the maintenance section Remove any adapters or components from the fixture 2 Using the precision open and short circuit from the calibration kit perform open and short circuit See the oper...

Page 87: ...ve the four screws located on the bottom at the corners of the unit Place the unit right side up on its feet and gently slide the plastic top off of the metal base It is necessary to slide the top gradually off of the fixture and the back panel since it fits tightly over these When the top is removed stand it on it s left side near the unit to avoid damaging the front panel cables The internal fus...

Page 88: ...all an impedance is measured on the constant drive voltage setting Over Range The impedance is beyond the SR715 720 s measurement ability on the current range If range hold is active change to a higher range Range Error Parameter in command is out of allowed range for that command Rcl Error Non volatile RAM has been corrupted User calibrations and settings may be lost If this error occurs frequent...

Page 89: ... V amplitude attenuator fail 6 0 1 V attenuator fail Freq Error i 5 The frequency clock generator failed its test i is an error code indicating failure point i error 0 100 Hz failed 1 120 Hz failed 2 1 kHz failed 3 10 kHz failed 4 100 kHz failed Gain Error i 8 The instrumentation amplifier failed its gain test i is an error code indicating failure point i error 0 the x2 gain failed 1 the x4 gain f...

Page 90: ...ng calibrated is in the fixture GPIB Problems First make sure that the GPIB interface is installed Second the GPIB address of the SR715 720 must be set to match that expected by the controlling computer The default GPIB address is 17 so it is a good idea to use this address when writing programs for the SR715 720 Any address from 0 to 30 may be set using the rear panel switches SW2 The SR715 720 w...

Page 91: ...to remove the nuts that hold the fixture to the mounting plate Slide the plastic lead catcher down until the leads can be removed Do this to one half of the fixture at a time to eliminate confusion Slide the lead catcher back up to the fixture and replace the nuts Attach the mounting bracket to the PCB and replace the top It may be easier to completely detach the fixture from the PCB before trying...

Page 92: ...nsert one of the wires in the hole at the center of the contact near the rod so that it will come out toward the center of the fixture Solder it on the backside of the contact and trim the wire as short as possible Repeat this for the remaining three contacts To reassemble the fixture select two housings each with a different colored lead Insert the coil springs in the plastic housings Press the c...

Page 93: ...across the inside surfaces of the tips Blow any residue off the tip REPLACEMENT The tips of the tweezers may need to be replaced from time to time Use the Allen wrench supplied with the tweezers 1 16 to remove the screw holding the tip Slide out the old tip and replace it with a new one making sure that the contact faces in Replace the Allen screw Repeat for the other side See the figure below ...

Page 94: ...MAINTENANCE 6 8 ...

Page 95: ...25 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 211 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 401 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 402 5 00244 554 1U Capacitor Polypropylene Radial C 403 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 404 5 00002 501 100P Capacitor Ceramic Disc 50V 10 SL C 405 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL C 406 5 00262 548...

Page 96: ...0 Rad C 1112 5 00035 521 47U Capacitor Electrolytic 25V 20 Rad C 1113 5 00258 520 15000U Capacitor Electrolytic 16V 20 Rad C 1114 5 00232 520 470U Capacitor Electrolytic 16V 20 Rad C 1115 5 00192 542 22U MIN Cap Mini Electrolytic 50V 20 Radial C 1116 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1117 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1118 5 00225 548 1U AXIAL Capacitor C...

Page 97: ...250 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1251 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1252 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1253 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1254 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1255 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1256 5 00225 548 1U AXI...

Page 98: ...1 1N4148 Diode D 107 3 00004 301 1N4148 Diode D 108 3 00004 301 1N4148 Diode D 109 3 00221 301 1N4004 Diode D 110 3 00221 301 1N4004 Diode D 201 3 00203 301 1N5711 Diode D 202 3 00203 301 1N5711 Diode D 601 3 00846 301 1 5KE6 8A Diode D 602 3 00846 301 1 5KE6 8A Diode D 603 3 00221 301 1N4004 Diode D 604 3 00221 301 1N4004 Diode D 605 3 00221 301 1N4004 Diode D 801 3 00004 301 1N4148 Diode D 802 3...

Page 99: ... 1407 3 00424 307 GREEN LED T 3 4 D 1408 3 00424 307 GREEN LED T 3 4 D 1409 3 00424 307 GREEN LED T 3 4 D 1410 3 00424 307 GREEN LED T 3 4 D 1411 3 00424 307 GREEN LED T 3 4 D 1412 3 00424 307 GREEN LED T 3 4 D 1413 3 00426 307 YELLOW LED T 3 4 D 1414 3 00424 307 GREEN LED T 3 4 D 1415 3 00426 307 YELLOW LED T 3 4 D 1416 3 00424 307 GREEN LED T 3 4 D 1417 3 00424 307 GREEN LED T 3 4 D 1418 3 00426...

Page 100: ...t Board PC3 7 00398 701 SR720 KEYBRD Printed Circuit Board Q 601 3 00408 340 IRFD1Z0 Integrated Circuit Thru hole Pkg Q 602 3 00408 340 IRFD1Z0 Integrated Circuit Thru hole Pkg Q 603 3 00022 325 2N3906 Transistor TO 92 Package Q 801 3 00140 325 2N2369A Transistor TO 92 Package Q 802 3 00021 325 2N3904 Transistor TO 92 Package Q 803 3 00021 325 2N3904 Transistor TO 92 Package Q 901 3 00021 325 2N39...

Page 101: ... 50PPM R 404 4 00206 407 8 06K Resistor Metal Film 1 8W 1 50PPM R 405 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 406 4 00189 407 41 2K Resistor Metal Film 1 8W 1 50PPM R 407 4 00666 407 73 2K Resistor Metal Film 1 8W 1 50PPM R 408 4 00138 407 10 0K Resistor Metal Film 1 8W 1 50PPM R 409 4 00068 401 300 Resistor Carbon Film 1 4W 5 R 410 4 00032 401 100K Resistor Carbon Film 1 4W 5 R 411 4...

Page 102: ... Resistor Carbon Film 1 4W 5 R 807 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 808 4 00054 401 200K Resistor Carbon Film 1 4W 5 R 809 4 00068 401 300 Resistor Carbon Film 1 4W 5 R 901 4 00032 401 100K Resistor Carbon Film 1 4W 5 R 902 4 00068 401 300 Resistor Carbon Film 1 4W 5 R 903 4 00068 401 300 Resistor Carbon Film 1 4W 5 R 1001 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 1002 4 00080 40...

Page 103: ...374 Integrated Circuit Thru hole Pkg U 504 3 00478 342 SR720 U504 EPROM PROM I C U 505 3 00058 340 AD7524 Integrated Circuit Thru hole Pkg U 506 3 00090 340 LF411 Integrated Circuit Thru hole Pkg U 507 3 00402 340 74HC4052 Integrated Circuit Thru hole Pkg U 508 3 00091 340 LF412 Integrated Circuit Thru hole Pkg U 509 3 00406 340 74HCT374 Integrated Circuit Thru hole Pkg U 510 3 00058 340 AD7524 In...

Page 104: ... 1106 3 00112 329 7805 Voltage Reg TO 220 TAB Package U 1107 3 00319 340 AD586JN Integrated Circuit Thru hole Pkg U 1108 3 00149 329 LM317T Voltage Reg TO 220 TAB Package U 1301 3 00289 340 HDSP H107 Integrated Circuit Thru hole Pkg U 1302 3 00288 340 HDSP H101 Integrated Circuit Thru hole Pkg U 1303 3 00288 340 HDSP H101 Integrated Circuit Thru hole Pkg U 1304 3 00288 340 HDSP H101 Integrated Cir...

Page 105: ...ire 22 UL1007 Z 0 0 00438 021 4 40X5 16PP Screw Panhead Phillips Z 0 0 00439 052 8 1 2 22 RED Wire 22 UL1007 Z 0 0 00440 052 2 1 2 22 RED Wire 22 UL1007 Z 0 0 00442 000 1 32 ADHES Hardware Misc Z 0 0 00523 048 5 5 8 18 Wire 18 UL1015 Strip 3 8 x 3 8 No Tin Z 0 0 00527 050 13 18 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Z 0 1 00123 113 9 PIN 18AWG OR Connector Amp MTA 156 Z 0 7 00297 735 SR725 1 Injec...

Page 106: ... 1 00110 130 30 PIN DIL Connector Male J 1502 1 00160 162 IEEE488 STAND Connector IEEE488 Standard R A Femal J 1503 1 00158 159 RS232 25 PIN D Connector D Sub Right Angle PC Male N 1501 4 00587 425 10KX7 Resistor Network SIP 1 4W 2 Common PC1 7 00400 701 SR720 Printed Circuit Board R 1501 0 00001 000 WIRE Hardware Misc R 1502 0 00001 000 WIRE Hardware Misc R 1503 4 00034 401 10K Resistor Carbon Fi...

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