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2-18

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TABLE  2-3      4819A SIGNAL ASSIGNMENTS

    Rear Panel Connector J2                            Internal Connector J3

     Pin # 

  Signals                   Signal                    Signals                Pin #

 

 

   DE-9P            Direction 

             DE-9S

 

DCD 

 

 

+V 

DCD 

1

 

TxD            

       

 ← 

 

TxD * 

2

 

RxD 

       

 →     

 

RxD * 

3

 

DTR         +V

 

 

 

DTR 

4

 

GND 

 

 −

 

     

GND 

5

 

DSR 

 

 

 

DSR 

6

 

RTS          +V 

 

 

RTS 

7

 

CTS 

 

 

 

CTS 

8

 

nc

 

 

 

− 

nc 

9

 

Notes:   

1. +V is + 9 Vdc through a 3.3 kohm resistor.  

 

 

2. * Standard setting.  TxD and RxD can be switched by setting jumper   

 

 

     W4 to the DTE position.

2.9.2.2  4819A Internal Connector J3

Internal connector J3 is a DE-9S connector with DCE type signal assign-

ments.  Signal RxD on pin 3 is the output to the internal serial device.  Signal 

TxD on pin 2 is driven by the internal serial device.  The RxD and TxD pins 

can be exchanged by rotating jumpers W4 90 degrees.  DCD and DSR are 

pulled up to an ‘ON’ state and RTS is jumpered back to CTS.

 

2.9.3  4829A Serial Connections

The 4829A has two right-angle 9-pin connectors for its serial interfaces.  

Connector J2 is the external RS-232 serial connector that protrudes through 

the rear panel.  Connector J3 is the internal RS-485 serial connector for 

connecting the 4829A to the serial device.  Signal pin assignments for both 

connectors are shown in Table 2-4.

2.9.3.1  4829A Rear Panel Connector J2

Rear panel connector J2 is a DE-9P connector with DTE type signal as-

signments similar to the signals in a PC COM port.  Signal TxD on pin 2 is 

the output signal and RxD on pin 3 is the input signal.  RTS and DTR are 

pulled high to the ‘ON’ state.  DTR is internally jumpered to CTS.

Содержание 4809A

Страница 1: ...ICS ELECTRONICS ICS a division of Systems West Inc MODEL 4809A 4819A 4829A and 4899A GPIB Modbus Interfaces Instruction Manual MODBUS...

Страница 2: ...us Interface Instruction Manual 7034 Commerce Circle Pleasanton CA 94588 Phone 925 416 1000 Fax 925 416 0105 Publication Number 120148 Web Site http www icselect com April 2017 Edition Rev 19 ICS ELEC...

Страница 3: ...ications The Model 4899A has been tested and found to comply with the limits for a Class A computing device pursuant to Subpart J of Part 15 of the FCC Rules and to comply with the EEC Standards EN 55...

Страница 4: ...ion Description GPIB Addressing 488 2 Commands SCPI Commands Modbus Commands Programming Guidelines and OEM Documentation Theory of Operation Block diagram Description Maintenance Troubleshooting and...

Страница 5: ...ii This page left intentionally blank...

Страница 6: ...4829A 4899A GPIB Modbus Interfaces are IEEE 488 2 GPIB to Serial Interfaces with special firmware to control Modbus RTU Slave devices from the GPIB or HP IB bus They let the user send simple commands...

Страница 7: ...second connector mates to one of ICS s GPIB Connector Address SwitchAssemblies which mount a GPIB connector and an GPIB address switch on the rear panel of the host chassis ICS s GPIB Connector Addres...

Страница 8: ...ac Adapter B Ship with British 230 Vac Adapter E Ship with European 230 Vac Adapter Base Model Number 4899A Minibox Product 4809A Board Product 114922 4809A board only version 4819A Board Product 1151...

Страница 9: ...es Primary addresses 0 30 1 4 3 Buffers GPIB input 2 kbytes GPIB output 1 kbytes Serial input output 256 bytes 1 4 4 488 2 Common Commands The4899AconformstoIEEESTD488 2 19A87 Whenaddressedtolistenin...

Страница 10: ...l pairs together for 2 wire networks The RX pair includes a termination network for biasing 2 wire networks Signal pinouts are listed in Table 2 4 1 5 1 Modbus RTU Messages Messages conform to the Mod...

Страница 11: ...RS 485 Specifications The 4809A 4829A and 4899A have differential RS 485 line drivers and receivers that provide RS 422 and RS 485 compatible signals The line drivers and receivers are designed to ope...

Страница 12: ...n Command Functions Factory Setting ADDRess Sets GPIB bus address 4 EXT Enables External GPIB Address Switch OFF 4809A only BAUD Sets transmit receive baud rate 9600 PARity Sets parity type NONE CHECK...

Страница 13: ...current GPIB address by blinking the front panel LEDs for one half second The GPIB address is the sum of the binary bit weights The LED bit weights are RDY TALK LSTN SRQ ERR 16 8 4 2 1 Any errors fou...

Страница 14: ...4 kg including adapter Temperature Operating 10 C to 55 C Storage 40 C to 70 C Humidity 0 90 RH without condensation Shock Vibration Normal handling only Construction All metal case Power 9 to 32 Vdc...

Страница 15: ...1 10 1 Figure 1 1 4899A Outline Dimensions 18 92 cm Side View 14 15 cm End View 3 86 cm 254 cm 0 95 cm max connector...

Страница 16: ...to 55 C Storage 40 C to 70 C Humidity 0 90 RH without condensation Shock Vibration Normal handling only Construction Flame retardant printed circuit board Power 5 0 25 Vdc 300 MA regulated 5 5 to 12 V...

Страница 17: ...ULL PWR TLK BSY 1 4819A or 4829A J1 GPIB Connector J2 Serial Connector J3 Device Serial Connector Status LEDs 4 50 4 00 0 190 dia mounting holes 4 plcs 0 300 dia mounting pads Mounting Blocks 2 plcs 0...

Страница 18: ...condensation Shock Vibration Normal handling only Construction Flame retardant printed circuit board Connector shells grounded to chassis supports and mounting brackets Power 5 0 25 Vdc 300 MA regula...

Страница 19: ...S EMI RFI Meets limits for part 15 Class A of US FCC Docket 20780 and complies with EEC Standards EN 55022 and 50082 1 CE Certificate of Compliance reproduced in Figure 1 4 UL CSA VDE AC Wall adapter...

Страница 20: ...rer s Address 473 Los Coches Street Milpitas CA 95035 USA Importer s Name Importer s Address Type of equipment GPIB to Serial Converter Model No 4899 Serial No Thru Year of manufacturer I the undersig...

Страница 21: ...4829A 4899A Instruction Manual 113640 L Horizontal GPIB Connector Address Switch Assembly Dash number is cable length from 10 to 90 CM long 90 CM standard 113642 L VerticalGPIBConnector AddressSwitch...

Страница 22: ...ll make arrangements for the unit to be repaired or replaced without waiting for the claim against the carrier to be settled 2 2 SHIPMENT VERIFICATION Take a moment to verify the shipment Each shipmen...

Страница 23: ...mounting kit 4 Connect the AC adapter to the 4899A and to the AC power Turn the unit on and verify that it passes its selftest and that it indicates the correct GPIB address Use the IDN query to verif...

Страница 24: ...to the power supply to avoid noise problems Set jumper W1 to REG for unregulated 5 5 12 volt power to P1 for regulated 5 volt power 5 Plug in the GPIB and serial cables and connect the unit to the GPI...

Страница 25: ...rd and mounting blocks 2 Mounting holes are 0 150 dia thru 3 Cutout A is 1 575 in x 0 625 in with 0 150 dia holes 4 Cutout B is 0 875 in x 0 450 in D shell with 10 slope to bottom and with 0 125 dia h...

Страница 26: ...tings in Table 1 1 to determine if your unit needs to be reconfigured before it can send data to the serial device If the board needs to be reconfigured follow the instructions in Sections 2 4 2 8 to...

Страница 27: ...easiest way to configure the unit is to use ICS s Minibox configuration program niconf_w exe which guides the user through a menu driven configuration procedure niconf_w exe runs withanyICS NationalIn...

Страница 28: ...un and display the Support CD Selection Window Click Configure GPIB Interfaces to run the niconf_w exe program or Install Keyboard Utilities to install the GPIBkybd program You can always download nic...

Страница 29: ...PIB Bus Cable AC Adapter 4899A PC with GPIB Controller Card a 4899A Configuration Setup Connect the 4809A 4819A or 4829A to the GPIB controller card in the PC or to a USB GPIB Controller as shown in F...

Страница 30: ...4 04 10 and click the SET button The factory default set ting is 4 If you do not know the unit s GPIB address turn the unit off and back on The unit will blink its GPIB address on the front panel LED...

Страница 31: ...ter Y to set PSC 0 N to set PSC 1 or click the appropriate boxes The program may ask if you want to lock the parameters so that they cannot be changed by the end user The configuration program automat...

Страница 32: ...the GPIB controller as shown in Figure 2 2 Run the program and if required use anAbort REN or a take control type command to have the bus controller assert REN Then turn the unit on 2 Determine the un...

Страница 33: ...a response if you just press Send The following example shows how to change and query the baud rate SYST COMM SER BAUD 19200 sets the baud rate SYST COMM SER BAUD queries the baud rate should reply 1...

Страница 34: ...hat one of the connectors be used to connect it to the GPIB bus The unused connector should be left open 2 8 2 1 GPIB Connector J1 TheGPIBSignal pinassignmentsforJ1areidenticaltoastandardIEEE 488 conn...

Страница 35: ...the 4809Areads the five address lines ADSW1 ADSW5 if the external address switch is enabled Connector J2 mates with ICS s GPIB Connector Address Switch Assem blies These assemblies are small business...

Страница 36: ...1 1 LSB ADSW3 8 GRY 1 4 ADSW2 9 WHT 1 2 NRFD 10 BLK 1 GPIB Signals REN 11 BRN2 DAV 12 RED 2 IFC 13 ORG 2 NDAC 14 YEL 2 EOI 15 GRN 2 ATN 16 BLU 2 SRQ 17 VIO 2 DIO1 18 GRY 2 DIO2 19 WHT 2 DIO3 20 BLK 2...

Страница 37: ...4 to drive remote LEDs Each signal is low true and can sink 3 mA Use a resistor in series with 5 Vdc to limit the current to LED Connect the LED cathodes to the driver signals The recommended resistor...

Страница 38: ...Send A Data Set Ready Ground Signal Detected A Signal Detected B Clear to send B Send Data B Receive Data B 4809A Talk LED Dvr Request to send B Data Terminal Rdy A 4809A Listen LED Dvr Data Terminal...

Страница 39: ...ce The RxD and TxD pins can be exchanged by rotating jumpers W4 90 degrees DCD and DSR are pulled up to an ON state and RTS is jumpered back to CTS 2 9 3 4829A Serial Connections The 4829A has two rig...

Страница 40: ...torwithSDandRDdifferentialsignal pairs The SD and RD signal pairs are a four wire full duplex interface The SD and RD signal pairs can be jumpered together on the 4829A board for half duplex operation...

Страница 41: ...A RS 232 connection to a Watlow F4 Temperature Controller Both interfaces transmit on pin 2 and receive on pin 3 1 2 3 4 5 6 7 25 4899A or 4809A WATLOW F4 4899A 4809A TXD RXD 1 12 13 14 15 16 Figure 2...

Страница 42: ...work so the Modbus can respond to the message Two wire RS 485 networks also need termination networks to bias the lines inthe mark statewhenneitherunitistransmitting Theterminationnetworks are made up...

Страница 43: ...c and ground provided by the Watlow F4 Temperature Controllers 1 2 14 3 16 7 25 4899A or 4809A WATLOW F4 1 11 12 13 14 15 16 WATLOW F4 T R T R 1K 1K 120 1 11 12 13 14 15 16 Figure 2 14 RS 485 Network...

Страница 44: ...RS 485 Network connections to a Watlow EZ Zone Controller Figure 16 shows an 4829A driving a single Watlow EZ Zone Controller with it RS 485 output The 4829A has an internal termination network with...

Страница 45: ...REG P1 for direct regulated 5 Vdc power REG for unregulated DC power W2 Set for EPROM size Not user changeable 512 W3 Write Enable Installed enables saving setup parameters Installed in EEPROM Remove...

Страница 46: ...5 Vdc regulated power source REG selects the regulator output for 5 5 to 15 Vdc power W3 Default Install and power cycle the unit to reset the unit to Omitted its factory default settings Leave out fo...

Страница 47: ...ut for 5 5 to 15 Vdc power W3 Default Install and power cycle the unit to reset the unit to Omitted its factory default settings Leave out for normal operation W4 Connects SD pair to RD signal pair In...

Страница 48: ...its case fitting the PC board into the tracks on each side of the case Be sure the switch and LEDs are correctly aligned before pushing the switch through the front panel Replace the two rear panel s...

Страница 49: ...2 28 2 UP W8 W3 WR ENA W9 W6 Serial GPIB SW Y1 U14 W1 422 232 CT CV CT CV W7 W5 W4 422 232 422 232 CT CV PRL DEFAULT Figure 2 20 4899A Jumper Locations...

Страница 50: ...n the rack mounting kit Push the unit down until it rests flat on the kit and the feet are in the four holes 2 Repeat step 1 for a second unit if two units are being held in one rack mounting kit 3 Al...

Страница 51: ...2 30 2 This page left intentionally blank...

Страница 52: ...he 4899A responds to three types of commands 1 IEEE 488 2 Common Commands in Table 3 2 These include the IDN and ESR queries and the SAV 0 save command 2 SCPI Commands in Table 3 3 are for setting int...

Страница 53: ...o the 4899Aover the GPIB bus the 4899Acommunicates with the selected Modbus device Modbus commands should not be mixed or concatenated with IEEE 488 2 or SCPI commands If the 4899A s message packet is...

Страница 54: ...er can control an RS 232 Modbus device from the serial connector or from the 4819A s GPIB interface However both interfaces cannot be used at the same time Once the GPIB interface is activated the ser...

Страница 55: ...for address setting instructions 3 3 2 4809AAddress External Address Switch The 4809A s GPIB address can also be set by connecting the 4809A to an external address switch Connector J2 contains the ext...

Страница 56: ...d or that the 4899A needs service There are four major sources of SRQs each of which is summarized in a bit in the Status Byte Register Three of the sources are event registers with their own enabling...

Страница 57: ...3 6 3 Flash Data Corrupted Figure 3 1 48x9A Status Reporting Structure Note 1 Modbus Register codes are listed in Table 3 5 on page 3 22...

Страница 58: ...mplete event has no meaning for either unit Table 3 1 ESR BIT DEFINITIONS Bit Bit Event Description Weight 7 128 PON The Power on event occurs at power turn on and can be used to signal a power off on...

Страница 59: ...to the Question able Event Register The Questionable Event Register bits becomes true 1 when the positive transition bit is enabled and the associated condition register bit makes a 0 to 1 transition...

Страница 60: ...orts the WTG Waiting for Trigger status and the Local Lockout and Remote GPIB interface states The WTG bit is true when the 4899A has been armed and is waiting for a trigger The following commands dem...

Страница 61: ...values Use the PSC 0 com mand to disable the PSC flag and save the current Enable and Transition register values The following example saves the current settings which enables bits in the Operation a...

Страница 62: ...y if CLS is the first message in the com mand line Sets Event Status Enable Register to value value is an integer between 0 and 255 whose binary equivalent cor responds to the state 1 or 0 of bits in...

Страница 63: ...ted 4899A operations have been finished Places an ASCII character 1 into the 4899A s Output Queue when all pend ing selected 4899A operations have been finished Controls the automatic power on clearin...

Страница 64: ...e is an integer be tween 0 and 255 whose binary equivalent corresponds to the state 1 or 0 of bits in the register If value is not between 0 and 255 an Execution Error is generated 4899A returns the v...

Страница 65: ...noted The SCPI commands are not case sensitive The portion of the command shown in capitals denotes the abbreviated form of the keyword Either the abbreviated or whole keyword may be used when enteri...

Страница 66: ...RS485 0 1 or OFF ON 0 ERRor 0 No error VERSion 1994 0 STATus OPERation Status Inputs WTG EVENt bit 0 1 and 5 active 0 CONDition bit 0 1 and 5 active 0 ENABle bit 0 1 and 5 active 0 ENABLE PTRansition...

Страница 67: ...re required A list of numbers is separated by commas or uses a colon to denote a range of numbers 8 Numeric entries conform to IEEE 488 2 section 7 7 2 4 for decimal numeric param eters 9 ASCII format...

Страница 68: ...nenablesthe4809A sexternaladdressswitchinputsto be used to input a switch setting for the GPIB address Off uses the value saved in E2 ROM memory Does not apply to the 4899A Values 0 1 or OFF ON SERial...

Страница 69: ...condition register associated with the command ENABle 0 Sets the enable mask which allows the true conditions in the associated event register to be reported in the summary bit PTRansition h7FFF Sets...

Страница 70: ...function CALibrate Starts calibrate branch IDN string Sets user IDN message String is up to 72 characters and consists of four fields manufacturer model code serial number and firmware revision separ...

Страница 71: ...s a packed binary value with 1 bit per coil 8 coils per byte 1 ON RI reg ninp Read Discrete Inputs Command code 0x02 Reads discrete inputs User specifies starting address in register reg and number of...

Страница 72: ...oating point value in low byte to high byte order The specified register reg contains the lower two bytes and the next higher register contains the upper two bytes WC reg b Write Coil Command code 0x0...

Страница 73: ...imeout setting E Read Error Command Reads and clears the Modbus Error Register and bit 6 in the Event Status Register Returns a error code whose value is 0 to 255 Current error values are 0 No errors...

Страница 74: ...rors and confusing the GPIB to Modbus Interface 3 8 1 General Configuration Guidelines New units are factory set so that they are ready to be used when received Table 1 1 lists the Factory Configurati...

Страница 75: ...ead one 16 bit value from register 0 With Watlow products register 0 is the Watlow Model number register The is optional and is included so programs like ICS s GPIB Keyboard control programs can autom...

Страница 76: ...6 bit registers The value is assumed to have three decimal places 3 8 6 32 Bit Write To write a set point of 1250 degrees which is really 1250 000 to Regis ters 27 and 28 multiply the setpoint value S...

Страница 77: ...laces Reading MSW 65536 LSW 1000 3 8 8 Floating Point Variables Some new Modbus devices like Watlow s EZ PM series controllers use two consecutive register to control a value or to read back a process...

Страница 78: ...e cific Modbus device Some devices fail to respond within the default time period because they perform periodic calibrations The recommendation is that your program should have a built in recovery rou...

Страница 79: ...ause and clear the SRQ so another error will cause another SRQ In case one this is done by reading the Modbus Error Register with the E query In case two the Questionable Event Register must be read t...

Страница 80: ...ngs The saved configuration is recalled and the I O settings restored to their saved state at power turn on or by the RCL 0 command WARNING Because the Nonvolatile Memory has a finite number of write...

Страница 81: ...ture The OEM needs to define what the digital inputs mean if they are part of the system how to enable SRQs and how to read the registers The SCPI Standard requires that the SCPI command tree and SCPI...

Страница 82: ...IEEE 488 bus and a Modbus slave device over a serial link The 4899A is made up of seven major elements most of which are interconnected to the microprocessor by a common data address and control sign...

Страница 83: ...utted at the serial interface SCPI commands and IEEE 488 2 commands are parsed and used to set control parameters perform an operation or query a parameter Responses are placed in the GPIB buffer so t...

Страница 84: ...ys its current GPIB address setting on the front panel LEDs Bit weights are read from right to left with the least significant bit on the far right The RDY LED comes on to indicate a successful comple...

Страница 85: ...PI commands and IEEE 488 2 commands are parsed and used to set the 4819A s configura tion perform an operation or query a parameter Responses are placed in the GPIB buffer so they can be returned to t...

Страница 86: ...he front panel The error pattern is repeated until the unit is turned off Just after completing the self test routine the 4819A displaysitscurrentGPIBaddresssettingonitsLEDs TheRDYLEDcomes on to indic...

Страница 87: ...to 12 volt DC power to 5 Vdc to run the 4819A s circuits A jumper on the 4819A bypasses the regulator so that the 4819A can be run from regulated 5 volt DC power A DC DC converter in the RS 232 transm...

Страница 88: ...coming serial mes sage is buffered and then retransmitted to the internal serial device The serial signals to the internal device are differential RS 485 signals Internal jumpers connect the transmit...

Страница 89: ...4 8 4 This page intentionally left blank...

Страница 90: ...ver if the interfaces are used in an application where the IEEE 488 bus cables are frequently changed or if the input signals appear erratic the GPIB connector may require clean ing to remove wax and...

Страница 91: ...listed in Table 5 1 5 3 2 Operating Failures Use the fault isolation information in Table 5 2 to narrow the operational problem down to a specific area The majority of installation faults can be fixed...

Страница 92: ...899A U7 in 4809A or U2 in 4819A Defective Flash that cannot be written to Replace part DefectivedecoderGAL Testand orreplace GAL U3 in 4899A U16 in 4809A or U5 in 4819A Flash loose in its socket or ha...

Страница 93: ...ress setting Wrong firmware or GPIB chip for hardware configuration Check hardware configuration andchangefirmwareorreplaceGPIB Control ler chip with NI 7210 U8 in 4819A Wrong CPU type Should be Zilog...

Страница 94: ...Unit shows a blinking Self test fault Check Self Test errors in LED at power turn on Table 5 1 ERR LED on at Flash data lost Use CLS to clear the LED power turn on Use CAL DATE command to enternewdate...

Страница 95: ...th the E command No communication Wiring error CheckRS 232orRS 485 with Modbus device cablewiringagainstfigures in Section 2 Modbus TXD signal must go to 48x9A receive input Use an RS 232TrackerorDVMt...

Страница 96: ...s CheckModbusErrorregister for Modbus problems Faulty or missing Modbus timeout Check Modbus Error Register Modbus responses setting withtheE queryforatime out error Error 101 UseDcommandtolengthen ti...

Страница 97: ...ettings If that does not work use the hardware default jumper 1 Power the board off 2 Locate the default jumper and place a shorting jumper on it See Section 2 11 for jumper locations 3 Power the boar...

Страница 98: ...ved over the phone as opposed to returning a unit for repair 2 Write a description of the problem and attach it to the material be ing returned Describe the installation system failure symptoms and ho...

Страница 99: ...5 10 5 This page left intentionally blank...

Страница 100: ...ial Data Communications Background A 15 A2 1 Introduction to Serial Communication A 15 A2 2 RS 232 Standard A 18 A2 3 RS 422 and RS 485 Standards A 20 A2 4 RS 530 Pinouts A 21 A2 5 Serial Interface Pr...

Страница 101: ...controller protocols are built in to the PC2 drivers All IEEE 488 2 common commands queries and SCPI com mands are placed in the output command string by the user and are not part of the PC2 driver so...

Страница 102: ...lersandmanydevices theIEEE488driverspecifications limit the total number of units on one bus system to 15 Only one controller can be the controller in charge at any given time Control originates with...

Страница 103: ...s set true by the control ler in charge while it is sending interface messages or device addresses The messages are transmitted on the seven least significant data lines and are listed in the MSG colu...

Страница 104: ...mmands MLA My listen address controller to self MTA My talk address controller to self LAD Device listen address TAD Device talk address SAD Secondary Device address device optional ad dress UNL Unlis...

Страница 105: ...D GROUP LISTEN ADDRESS GROUP TALK ADDRESS GROUP SECONDARY COMMAND GROUP PRIMARY COMMAND GROUP PCG LSD MSD MSG GTL SDC PPC GET TCT ASCII DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US MSG L...

Страница 106: ...7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 DIO5 DIO6 DIO7 DIO8 REN GND TW PAIR W DAV GND TW PAIR W NRFD GND TW PAIR W NDAC GND TW PAIR W FC GND TW PAIR W SRQ GND TW PAIR W ATN SIGNAL GROUND D...

Страница 107: ...ntrol Operation Complete Standard Event Status Register ESR 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 Logical OR Standard Event Status Enable Register ESE NRf ESE Queue Not Empty 7 5 4 3 2 1 0 Logical OR 7 6 3...

Страница 108: ...expected A1 2 2 IEEE 488 2 Reporting Structure With IEEE 488 2 status reporting was enhanced from the simple serial poll response byte in IEEE 488 1 to the multiple register concept shown in Figure A...

Страница 109: ...Command Devices that support parallel polls must support the following three com mands IST Individual Status Query PRE Parallel Poll Register Enable Command PRE Parallel Poll Register Enable Query De...

Страница 110: ...tatus Byte Register contents plus the MSS bit in response to a STB query The MSS bit is cleared when the condi tion is cleared 488 2 restricts the Device Clear to only clearing the device s buffers an...

Страница 111: ...age and syntax Asecond benefit of SCPI is that its English like structure and words are self documenting eliminatingtheneedsforcommentsexplainingcrypticinstru ment commands A third benefit is the redu...

Страница 112: ...uts it back at the root node IEEE 488 2 common commands and queries can be freely mixed with SCPI messages in the same programmessagewithoutaffectingtheaboverules FigureA 5showssome compound command e...

Страница 113: ...re used as a way of listing multiple values Channel lists are enclosed in parenthesis and start with the ASCII character The values are separated with commas The length of the channel list is determin...

Страница 114: ...rmat Typical computer baud rates and their uses are 110 for old mechanical teletypes 300 1200 for low speed devices an older modems 9600 to 38400 baud for high speed devices and newer modems Data form...

Страница 115: ...form as single 8 bit characters or in hex form as a pair of the ASCII characters 0 through 9 and A through F Each Hex character represents 4 binary bits so two Hex characters are needed for each 8 bit...

Страница 116: ...to convert the serial data bits into tones that will pass through the telephone system s 300 to 3000 Hz voice band For low baud rates up to 1200 Hz the modems convert the bits into two tones frequenc...

Страница 117: ...opping any line normally means the receiving device s buffer is full or it is busy with the last message Another method of controlling the data flow is to imbed X on X off char acters in the data mess...

Страница 118: ...lly RS 232 signals are bipolar and are referenced to a common ground AB on pin 7 Transmitted signals must be between 5 and 15V or 5 and 15V into 3000 to 7000 ohm loads Maximum open circuit transmit te...

Страница 119: ...ngle ended RS 232signals TheRS 422differentialsignalsrequireadifferentialreceiver and are not referenced to Signal Ground Differential transmitted signals applied to the interconnecting cable are 2 to...

Страница 120: ...nals A2 5 Serial Interface Problems Most of the problems that arise when connecting serial devices can be avoided if the user will compare the signals on both devices interfaces before plugging them t...

Страница 121: ...r as shown in Figure A 9 b The Address Switch is an eight position rocker switch For ICS board products the five left most switches set the GPIB address The bit weights are shown in Figure A 10 Up is...

Страница 122: ...a on the host chassis rear panel as shown in Figure A 11 Leave enough room inside for the flat ribbon cable bend radius 3 Machine the cutouts shown in Figure A 12 If the rear panel is thicker than 0 0...

Страница 123: ...e to the board so it avoids any high RFI or electrical noise area Plug the cable into J2 6 Mark or silkscreen the switch functions onto the rear panel as shown in Figure A 10 Identify the 5 address ro...

Страница 124: ...3 Holes are 0 180 dia 2 plcs 4 Allow 0 25 inches for cable bend radius 0 920 0 420 1 578 1 842 1 200 0 635 Notes 1 All dimensions are in inches 2 D cutout radius is 0 2 inches 3 Holes are 0 180 dia 2...

Страница 125: ...A 26 A3 This page intentionally left blank...

Страница 126: ...Specifications 1 13 Serial Connections 2 16 Watlow 96 Connections 2 21 4829A Block Diagram 4 6 Block Diagram Description 4 6 Description 1 2 EZ Zone connections 2 23 Installation Guide 2 4 Jumper sett...

Страница 127: ...1 Connections GPIB 2 13 Serial 2 16 Connector Switch Board Assembly A 23 Cable length A 22 Cutouts A 25 Connectors 4809 1 11 4819 1 13 4899 1 9 Copyright release 3 30 D Digital Inputs Monitoring chang...

Страница 128: ...4 488 2 Conformance information 3 11 488 2 required status reporting capabilities A 7 A 8 488 2 status reporting structure 3 5 Address ranges 1 4 Bus Figure A 3 SCPI commands A 12 SCPI command structu...

Страница 129: ...3 2 5 1 Theory of 4 1 Operational Registers 3 9 Outline dimensions 4819 1 12 Output Queue 3 10 P Physical 4809 1 11 4819 1 13 4899 1 9 Programmable functions 1 7 Programming 32 bit variables 3 25 3 2...

Страница 130: ...1 5 Serial Interface Baud rates 1 5 Data character formats 1 6 Problems A 21 Shipment Verification 2 1 Specifications 1 3 RS 232 1 6 RS 485 RS 422 1 6 SRQs Generating from Modbus Errors 3 28 Standard...

Страница 131: ...I Index 6 This page left intentionally blank...

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