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GPIB-232CV-A User Manual

1. EE HH d sess m IBM PC Digital Multimeter Serial Device GPIB Device Figure 3 2 Example of C Mode System Setup GPIB 232CV A User Manual 3 2 WWW ni com Chapter 3 Operation of the GPIB 232CV A D Mode Overview In D mode the GPIB 232CV A acts as another device on the bus Figure 3 3 shows the D mode system layout Controller GPIB 232CV A GPIB GPIB GPIB Device Device Device Serial Device Figure 3 3 D Mode System Layout In D mode the GPIB 232CV A can act only as a GPIB Talker or Listener Do not pass control to the GPIB 232CV A when using D mode If you do the GPIB circuitry in the GPIB 232CV A accepts control and immediately asserts the ATN signal a system error condition that you should avoid Because the GPIB 232CV A is not System Controller in D mode it expects to receive GPIB commands from the Controller In Charge CIC If the GPIB 232CV A receives the universal Device Clear DCL command or is addressed to listen and receives the Selected Device Clear SDC command it clears its internal data buffers and resets to its power up state Neither Trigger GET nor Go To Local GTL have any effect on the GPIB 232CV A Data Transfers in D Mode When you are ready to send data to the GPIB 232CV A in D mode address the GPIB 232CV A to listen if not already in listen only mode All GPIB data received
2. enne nennen nennen enne 1 7 GPIB Connector teretes 1 8 Chapter 2 Configure and Install Your Hardware Configure Your Hardware essent enne 2 1 Configure the GPIB 232CV A 2 2 Configure the Serial Port Parameters 2 5 Install Y out HardWate 4 iiec ceo ees teecoetece tee co eee tese etse ee tree 2 6 Step 1 Shut Down Your System essere nennen enne 2 6 Step 2 Verify That You Have a Null Modem Serial Cable 2 7 Step 3 Connect the Cables nter netten 2 7 Step 4 Power on Your System and Switch on Your GPIB 232CV A 2 8 Chapter 3 Operation of the GPIB 232CV A Choosing Between D Mode and C Mode Configuration sess 3 1 When to Use D Mode eet ette ime bete ee cea ig 3 1 When to Use C Mode BEA ceti end ie ceni etes 3 2 TY Mode OVERVIEW iecore eee tete et eee eee ceo eee pee eee eene Hee eeu 3 3 Data Transfers an D Mode e ertet te ree 3 3 Choosing a Serial Port Buffer Size essere 3 4 National Instruments Corporation Vii GPIB 232CV A User Manual Contents Using the SRO Feature acaso e ient deuce 3 4 Conditions That Cause SRQ to be 3 5 Maximizing Perf
3. When the GPIB 232CV A serial input buffer is empty and the GPIB 232CV A receives a serial character to be sent along to the GPIB the SRQ signal is asserted This alerts the GPIB Controller that the GPIB 232CV A has data to send to a GPIB Listener The Controller can then address the GPIB 232CV A to talk so that the data can be read out of the GPIB 232CV A serial buffer When the serial buffer is empty the Controller can unaddress the GPIB 232CV A to talk and address other devices to transfer data on the bus SRQ is also asserted when the GPIB input buffer becomes empty When the GPIB 232CV A has emptied out the buffer it requests service indicating it is ready for more data The Controller can then readdress the GPIB 232CV A to listen and continue sending data until all the data is sent Maximizing Performance with SRQ If large amounts of data greater than the GPIB buffer size are sent over the GPIB to the GPIB 232CV A and the serial device is a very slow data acceptor the GPIB 232CV A internal GPIB data buffer might become full If this occurs the FULL indicator on the front panel illuminates and the GPIB transfer rate slows to approximately the same rate as the serial device that is accepting the data Because the maximum data transfer rate on the GPIB is only as fast as the slowest Listener the GPIB system performance may become unacceptable if other GPIB devices are required to transfer data on the bus To get maximum GPIB perf
4. GPIB 232CV A User Manual 1 2 cable configuration for 9 DTE to 25 pin DTE figure B 7 cable wiring scheme table B 6 interfacing without handshaking B 7 to B 9 custom cables B 9 minimum configuration cable B 8 9 pin DTE to 9 pin DTE figure B 8 9 pin DTE to 25 pin DTE figure B 8 DTR signal RS 232 port table B 2 E electrical characteristics AC version 1 DC version A 1 environment characteristics AC version 1 to 2 DC version A 2 equipment optional 1 2 F FULL LED table 1 5 fuse holder on AC front panel 1 3 fuse rating and type 1 G GET Trigger command 3 3 GND signal RS 232 port table B 2 Go To Local GTL command 3 3 GPIB connector overview 1 8 signals supported figure 1 8 WWW ni com GPIB 232CV A See also operation of GPIB 232CV A AC front panel 1 3 GPIB connector 1 8 inspecting for damage 1 3 optional equipment 1 2 overview 1 1 rear panel 1 5 requirements for getting started 1 2 RS 232 connector 1 7 side panels 1 6 to 1 8 top panel 1 4 to 1 5 GTL Go To Local command 3 3 H handshaking DCE Data Communications Equipment interfacing with handshaking B 3 to B 4 interfacing without handshaking B 4 to B 6 DTE Data Terminal Equipment interfacing with handshaking B 6 to B 7 interfacing without handshaking B 7 to B 9 hardware handshaking 3 11 to 3 12 overview 3 11 XON XOFF software handshaking 3 12 HP7475 GPIB plotter
5. signal asserted 3 3 choosing between D mode and C mode 3 1 to 3 2 choosing serial port buffer size 3 4 conditions causing SRQ assertion 3 5 data transfers 3 3 example of system setup figure 3 2 listen only mode operation 3 6 maximizing performance with SRQ 3 5 serial poll responses 3 6 system layout figure 3 3 Talker or Listener mode 3 3 GPIB 232CV A User Manual Index using SRQ feature 3 4 to 3 5 when to use 3 1 to 3 2 data buffering and handshaking See also handshaking hardware handshaking 3 11 to 3 12 overview 3 11 XON XOFF software handshaking 3 12 Data Communications Equipment DCE See DCE Data Communications Equipment Data Terminal Equipment DTE See DTE Data Terminal Equipment data transfers C mode 3 7 D mode 3 3 DCE Data Communications Equipment interfacing with handshaking B 3 to B 4 cable configuration for 9 pin DTE to 9 pin DCE figure B 4 cable configuration for 9 pin DTE to 25 pin DCE figure B 4 cable wiring scheme table B 3 interfacing without handshaking B 4 to B 6 custom cables B 6 minimum configuration cable B 5 9 pin DTE to 9 pin DCE figure B 5 9 pin DTE to 25 pin DCE figure B 5 DCL Device Clear command 3 3 diagnostic resources online D 1 documentation conventions used in manual xi related documentation xii DTE Data Terminal Equipment interfacing with handshaking B 6 to B 7 cable configuration for 9 pin DTE to 9 pin DTE figure B 7
6. suffix indicates that the signal is active low DIO1 1 DIO5 DIO2 2 DIO6 DIO3 3 DIO7 DIO4 4 DIO8 5 REN DAV 6 GND Twisted Pair with DAV NRFD 7 GND Twisted Pair with NRFD NDAC 8 GND Twisted Pair with NDAC IFC GND Twisted Pair with IFC SRQ GND Twisted Pair with SRQ ATN GND Twisted Pair with ATN SHIELD SIGNAL GROUND Figure 1 6 GPIB Connector and Signal Designations 1 8 WWW ni com Configure and Install Your Hardware This chapter describes how to configure and install your GPIB 232CV A Configure Your Hardware Before you configure your GPIB 232CV A verify that the voltage marked on the GPIB 232CV A or on the power supply matches the voltage that is supplied in your area UN Caution Do not operate your GPIB 232CV A at any voltage other than the one marked on your GPIB 232CV A Doing so could damage the unit Replacement fuses for the AC version must be the proper type and size For fuse specifications refer to Appendix A Specifications Your GPIB 232CV A is configured at the factory as follows e Dmode e GPIB primary address 5 SRQ feature disabled e Serial port is configured to 9600 baud 1 stop bit per character Parity generation checking disabled 7 data bits per character XON XOFF protocol disabled If you want to change any of the GPIB 232CV A characteristics you must change the config
7. 9 pin to 9 pin 1 m 182238 02 9 pin to 9 pin 2 m 182238 04 9 pin to 9 pin 4 m 181074 10 9 pin to 25 pin 1 m See Appendix B Interfacing to a Serial Device for more information regarding cable pinouts Step 3 Connect the Cables To connect the cables complete the following steps 1 Connect the serial cable to the GPIB 232CV A 9 pin D Sub connector and securely fasten the holding screws Connect the other end of the cable to your serial device Be sure to use only shielded serial cables and follow all RS 232 cabling restrictions 2 Connect the GPIB cable to the GPIB 232CV A 24 pin Champ connector and tighten the thumb screws on the connector Connect the other end to your GPIB system Be sure to use only shielded GPIB cables and follow all IEEE 488 cabling restrictions 3 If you have an AC version connect the power cord to the power receptacle on the front panel of the GPIB 232CV A then plug the supply into an AC outlet of the correct voltage If you have a DC version connect the DC power plug of the DC power supply to the power jack on the serial end of the GPIB 232CV A then plug the supply into an AC outlet of the correct voltage National Instruments Corporation 2 GPIB 232CV A User Manual Chapter 2 Configure and Install Your Hardware Step 4 Power on Your System and Switch on Your GPIB 232CV A GPIB 232CV A User Manual 1 Plug the power cords for your computer system into a power outlet and powe
8. DTE Figure B 6 Cable Configuration for 9 pin DTE to 9 pin DTE with Handshaking 14 lt 15 lt 16 Lo 17 5 Lo 18 E20 c3 GPIB 232CV A B c 21 9 pin DTE cx 22 P Lon 23 12 9 24 13 1 Serial Device 25 pin DTE Figure B 7 Cable Configuration for 9 pin DTE to 25 pin DTE with Handshaking Interfacing the GPIB 232CV A to a DTE without Handshaking If your serial device does not require or use the same hardware handshaking protocol used by the GPIB 232CV A you have two options e Use a minimum configuration null modem cable which does not support the hardware handshake lines and use XON XOFF software handshaking if necessary To create a minimum configuration cable connect the signals shown in bold italics in Table B 3 National Instruments Corporation B 7 GPIB 232CV A User Manual Appendix Interfacing to a Serial Device e Wire a custom cable that properly interfaces the GPIB 232CV A hardware handshaking protocol to the handshaking protocol of your serial device Minimum Configuration Cable The minimum cable configuration assumes that the serial device does not require external hardware handshaking The minimum configuration for a 9 pin to 9 pin null modem cable is shown in Figure B 8 Figure B 9 shows an equivalent 9 pin to 25 pin cable GPIB 232CV A Serial Device 9 pin DTE 9 pin DTE Figure B 8 Minimum Configuration for 9 pin DTE to 9
9. GPIB 232CV A It then readdresses the device to talk and passes any characters read from the GPIB port along to the serial port CR or LF Termination Mode If a command string to the GPIB instrument can be terminated with either a CR carriage return or lt LF gt linefeed character you can use either termination with CR or lt LF gt to readdress the GPIB device to send data To select CR mode set SW1 switch 6 to ON and 7 to OFF To select lt LF gt mode set SW1 switch 6 to OFF and 7 to ON In these modes when the GPIB 232CV A receives the terminating character from the serial port it addresses the device to talk so that any GPIB data can be input by the GPIB 232CV A Then any serial character received by the GPIB 232CV A signals the GPIB 232CV A to readdress the GPIB device as a Listener For example you might want to connect an HP7475 GPIB plotter to an IBM PC serial port using the GPIB 232CV A To then draw a line get plotter status and draw a circle you could use the following BASIC commands 10 OPEN COM1 9600 n 8 1 AS 1 Assumes GPIB 232CV A is at 9600 baud no parity 8 data bits 1 stop bit 20 PRINT 1 1000 1000 os Plot absolute to 1000 1000 then output status 30 LINE INPUT 1 RESPONSES Get status response from plotter 40 PRINT 1 cil100 Draw circle with radius of 100 units National Instruments Corporation 3 9 GPIB 232CV A User Manua
10. and Install Your Hardware Table 2 4 Configuration Parameters for SW2 Switches 1 through 3 Continued Switches 1 2 3 Indication OFF ON ON 19200 baud ON ON ON 38400 baud Table 2 5 Configuration Parameters for SW2 Switches 4 through 8 Switch Position Indication 4 OFF Odd parity ON Even parity 5 OFF Parity generation checking disabled ON Parity generation checking enabled 6 OFF 1 stop bit per character ON 2 stop bits per character 7 OFF 7 bits per character ON 8 bits per character 8 OFF XON XOFF protocol disabled ON XON XOFF protocol enabled Install Your Hardware After configuring the switch settings on your GPIB 232CV A complete the following steps to install the GPIB 232CV A Step 1 Shut Down Your System Before you connect the cables complete the following steps 1 Shutdown your system 2 Turn off your computer and unplug the power cord GPIB 232CV A User Manual 2 6 WWW ni com Chapter 2 Configure and Install Your Hardware Step 2 Verify That You Have a Null Modem Serial Cable You must use a null modem serial cable also known as a file transfer cable or a DTE to DTE cable to connect your computer to the GPIB 232CV A The following National Instruments cables are null modem serial cables Table 2 6 National Instruments Null Modem Serial Cables National Instruments Part Number Cable Type 182238 01
11. by the GPIB 232CV A is buffered and passed along to the serial device When you are expecting to receive data from the serial device address the GPIB 232CV A to talk and all data received over the serial port is passed along to the GPIB port National Instruments Corporation 3 3 GPIB 232CV A User Manual Chapter 3 Operation of the GPIB 232CV A Choosing a Serial Port Buffer Size data that is sent to the GPIB 232CV A is buffered and then passed along to the destination port Thus any serial data received is buffered and then passed along to the GPIB port whenever the GPIB 232CV A is addressed to talk The GPIB 232CV A has 256 KB of RAM for buffering In D mode this memory can be allocated between the serial and GPIB buffers in two possible configurations The size of the serial input buffer can be set to either 256 bytes SWI1 switch 7 set to OFF or 32 KB SWI switch 7 set to ON with the remainder of the 256 KB of RAM allocated to the GPIB buffer e Set the serial input buffer size to 256 bytes if only small amounts of data such as status information from a plotter are expected to be sent from the serial device to the GPIB 232CV A e serial input buffer size to 32 KB if you expect the serial device to send large amounts of data to the GPIB 232CV A such as an RS 232 instrument sending thousands of bytes of measurements In either case the remainder of RAM space is used as the GPIB input buffer Thus if a large
12. pin DTE 09 GPIB 232CV A 8 9 pin DTE 9 0000000000 kai c Com c H O Serial Device 25 pin DTE Figure B 9 Minimum Configuration for 9 pin DTE to 25 pin DTE GPIB 232CV A User Manual B 8 WWW ni com Appendix Interfacing to a Serial Device Custom Cables If your application requires a custom cable you can construct one if you have a thorough knowledge of the handshaking protocols involved Review the RS 232 characteristics of your serial device and build the cable to properly connect the handshake lines of the two devices If the documentation for your serial device does not provide a thorough explanation of its handshaking protocol the ANSI EIA 232 C standard is a good reference provided your device conforms to the RS 232 protocol Caution Although handshaking might not be required it is best to use some form of handshaking to prevent loss of data National Instruments Corporation B 9 GPIB 232CV A User Manual Application Examples This appendix contains two GPIB 232CV A application examples The first example shows how to use the GPIB 232CV A as a high speed print spooler and the second example shows how to connect a HP7475 GPIB plotter to an IBM PC running AUTOCAD Using the GPIB 232CV A as a High Speed Print Spooler Because mechanical printers and plotters are slow relative to the process
13. radio frequency energy and if not installed and used in strict accordance with the instructions in this manual and the CE Mark Declaration of Conformity may cause interference to radio and television reception Classification requirements are the same for the Federal Communications Commission FCC and the Canadian Department of Communications DOC Changes or modifications not expressly approved by National Instruments could void the user s authority to operate the equipment under the FCC Rules Class A Federal Communications Commission This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense Canadian Department of Communications This Class A digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe A respecte toutes les exigences du R glement sur le mat riel brouil
14. serial connector Figure 1 4 shows the location of the RS 232 and GPIB connectors and the DC power jack DC Power Jack DC version only GPIB 232C V A RS 232 lt IEEE 488 Controller D A C oL amp A NATIONAL d y PP INSTRUMENTS 7 lt AAT E og g V e o o o o o RS 232 Connector GPIB Connector Figure 1 4 Location of the Connectors and the DC Power Jack GPIB 232CV A User Manual 1 6 WWW ni com Chapter 1 Introduction RS 232 Connector The RS 232 port on the GPIB 232CV A is configured as a DTE Data Terminal Equipment and uses a standard 9 pin shielded D Subminiature male connector with screwlock assemblies The RS 232 connector accepts standard 9 pin D Subminiature female connectors Figure 1 5 shows a diagram of the serial connector and the signals supported For more information on the RS 232 signals refer to Appendix B Interfacing to a Serial Device No Connection No Connection RTS PAD TXD CTS DTR No Connection GND Figure 1 5 RS 232 Connector and Signal Designations National Instruments Corporation 1 7 GPIB 232CV A User Manual Chapter 1 Introduction GPIB 232CV A User Manual GPIB Connector The GPIB connector is a standard 24 pin shielded Champ female connector with metric screwlock hardware Figure 1 6 shows a diagram of the GPIB connector and the signals supported A
15. shielded cable GPIB 232CV A to IBM PC from National Instruments GPIB 232CV A User Manual 1 2 WWW ni com Chapter 1 Introduction Inspection Before you operate the GPIB 232CV A inspect the shipping container and its contents for damage Keep the packing material for possible inspection and or reshipment If the equipment appears to be damaged do not attempt to operate it Contact National Instruments for instructions If the damage appears to have been caused in shipment file a claim with the carrier GPIB 232CV A Panels The following sections describe the panels of the GPIB 232CV A AC Front Panel The power switch fuse holder and power cord receptacle are located on the GPIB 232CV A front panel on the AC version only Figure 1 1 shows the front panel of the AC version kN E 3 65 1 1 Figure 1 1 GPIB 232CV A AC Front Panel National Instruments Corporation 1 8 GPIB 232CV A User Manual Chapter 1 Introduction Top Panel The six light emitting diodes LEDs are located on the GPIB 232CV A top panel Figure 1 2 shows the top panel GPIB 232C V A RS 232 IEEE 488 Converter lt Figure 1 2 GPIB 232CV A Panel The LEDs show the current status of the GPIB 232CV A Table 1 1 describes each LED Table 1 1 LED Descriptions LED Indication POWER Indicates that power has been applied to the u
16. the EU EEC EEA must refer to the Manufacturer s Declaration of Conformity DoC for information pertaining to the CE Mark compliance scheme The Manufacturer includes a DoC for most every hardware product except for those bought for OEMs if also available from an original manufacturer that also markets in the EU or where compliance is not required as for electrically benign apparatus or cables Certain exemptions may apply in the USA see FCC Rules 815 103 Exempted devices and 15 105 c Also available in sections of CFR 47 The CE Mark Declaration of Conformity will contain important supplementary information and instructions for the user or installer Contents About This Manual RTI xi Related en eee xii Chapter 1 Introduction GPIB 232CV A cabdescvcvevseetessnieecedevesadesnscesceeess 1 1 What You Need to Get Started 1 2 Optional Equipment oett Ricette e rere 1 2 Inspection Raices hee 1 3 GPIB 232CV A Panels iae ee ee Eee eret ek refe do 1 3 AC Front Panel eene nen nennen ener 1 3 Top Panel te ET EPIO GUIDE a 1 4 1 5 Side Panel z eerte OE iid tecettcete eee 1 6 5 232
17. 2 4 WWW ni com Chapter 2 Configure and Install Your Hardware Configure the Serial Port Parameters You can use the DIP switch SW2 on the rear panel see Figure 1 3 GPIB 232CV A Rear Panel and Figure 1 4 Location of the Connectors and the DC Power Jack to configure the serial port parameters of the GPIB 232CV A Figure 2 2 shows the factory default setting BAUD RATE DATA FORMAT r HANDSHAKE 12345678 Sw2 Figure 2 2 Factory Default Switch Settings for SW2 In Figure 2 2 switches 1 through 3 are ON OFF and ON respectively indicating that the serial port is operating at 9600 baud Switches 4 and 5 are both OFF which indicates that parity is disabled Switch 6 is OFF which indicates 1 stop bit per character Switch 7 is OFF indicating that the 232 is using 7 bits character for its serial data transfers Switch 8 is OFF indicating that XON XOFF software handshaking is disabled Tables 2 4 and 2 5 show the possible configurations of SW2 and what the configurations indicate Default settings appear in bold italics Table 2 4 Configuration Parameters for SW2 Switches 1 through 3 Switches 1 2 3 Indication OFF OFF OFF 300 baud ON OFF OFF 600 baud OFF ON OFF 1200 baud ON ON OFF 2400 baud OFF OFF ON 4800 baud ON OFF ON 9600 baud National Instruments Corporation 2 5 GPIB 232CV A User Manual Chapter 2 Configure
18. 20 ON OFF ON OFF ON GPIB Primary Address 21 OFF ON ON OFF ON GPIB Primary Address 22 ON ON ON OFF ON GPIB Primary Address 23 OFF OFF OFF ON ON GPIB Primary Address 24 ON OFF OFF ON ON GPIB Primary Address 25 OFF ON OFF ON ON GPIB Primary Address 26 ON ON OFF ON ON GPIB Primary Address 27 OFF OFF ON ON ON GPIB Primary Address 28 National Instruments Corporation 2 3 GPIB 232CV A User Manual Chapter 2 Configure and Install Your Hardware GPIB 232CV A User Manual Table 2 1 Configuration Parameters for SW1 Switches 1 through 5 Continued Switches 1 2 3 4 5 Indication ON OFF ON ON ON GPIB Primary Address 29 OFF ON ON ON ON GPIB Primary Address 30 ON ON ON ON ON Listen Only Operation D Mode or No Addressing Performed C Mode Table 2 2 Configuration Parameters for SW1 Switches 6 and 7 Switches Indication 6 7 D Mode C Mode OFF OFF SRQ Disabled and Timeout Termination Small Serial Buffer ON OFF SRQ Enabled and CR Termination Small Serial Buffer OFF ON SRQ Disabled and LF Termination Large Serial Buffer ON ON SRQ Enabled and No Swapping Large Serial Buffer Table 2 3 Configuration Parameters for SW1 Switch 8 Switch 8 Position Indication OFF GPIB 232CV A Operates in D Mode ON GPIB 232CV A Operates in C Mode
19. B 232CV A User Manual Xii www ni com Introduction This chapter describes the GPIB 232CV A lists what you need to get started and optional equipment you can order and describes the panels on the GPIB 232CV A GPIB 232CV A Overview The GPIB 232CV A has a powerful 8 bit microcomputer tailored for use as an IEEE 488 to RS 232 protocol converter Both the RS 232 serial port and the GPIB IEEE 488 port are interrupt driven and feature extremely fast response times to external data transfers The GPIB 232CV A can transparently convert data between the two ports so that control codes or special commands are not required Data transfers in either direction are possible at all times The GPIB 232CV A microprocessor contains an integrated direct memory access DMA controller for high speed data transfers from the GPIB circuitry The GPIB 232CV A also increases the efficiency of the interface system by using a 256 KB RAM buffer to isolate the slower device from the faster port You can use the GPIB 232CV A to interface either a GPIB Controller or a GPIB device to a computer or instrument with a RS 232 port The RS 232 serial port is fully compatible with all electrical specifications in the RS 232 standard The operating system of the GPIB 232CV A is contained in read only memory ROM and can address up to 256 KB of dynamic random access memory RAM The operating system programs and maintains the LSI GPIB Controller chip the NAT4882 whi
20. Celsius CIC Controller In Charge CR carriage return CSA Canadian Standards Association CTS Clear to Send DAV Data Valid DC direct current DCE Data Circuit terminating Equipment DIO digital input output DIP dual inline package DMA direct memory access DTE Data Terminal Equipment DTR Data Terminal Ready National Instruments Corporation G 1 GPIB 232CV A User Manual Glossary EIA EMI EOI FCC GND GPIB hex IEC IEEE IFC KB LED LF LSI OZ PC RAM REN ROM RTS RXD SRQ GPIB 232CV A User Manual Electronic Industries Association electromagnetic interference end or identify Federal Communications Commission grams ground General Purpose Interface Bus hexadecimal hertz International Electrotechnical Commission Institute of Electrical and Electronic Engineers Interface Clear inches kilobytes of memory light emitting diode linefeed large scale integration meters ounces personal computer random access memory Remote Enable read only memory Request to Send Receive Data seconds Service Request G 2 www ni com TXD UART UL VAC VDC Transmit Data Universal Asynchronous Receiver Transmitter Underwriters Laboratories volts volts alternating current volts direct current National Instruments Corporation G 3 Glossary GPIB 232CV A User Manual Index A AC front panel 1 3 application examples C 1 to C 4 connecting HP7475 GPIB plotter to PC serial p
21. Controller that addresses a single GPIB device to talk or listen C mode When to Use D Mode The GPIB 232CV A should be set to operate in D mode if you want to connect a serial device to a GPIB system that has a GPIB Controller responsible for addressing the GPIB 232CV A to talk or listen An example of a system requiring D mode includes a serial device such as a printer connected to a GPIB system with an existing GPIB Controller National Instruments Corporation 3 1 GPIB 232CV A User Manual Operation of the GPIB 232CV A such as an IBM PC AT computer with a National Instruments AT GPIB IEEE 488 2 board installed as shown in Figure 3 1 Wo WQOPIB Device VY 000 Serial Cable GPIB Cables VONSDODSSM A a aa a a cn V Printer Zo E e MP Serial Device GPIB 232CV A IBM PC AT GPIB Controller Figure 3 1 Example of D Mode System Setup When to Use C Mode The GPIB 232CV A should be set to operate in C mode when transferring data between a GPIB device that has no Controller capabilities and a serial device An example of a system requiring C mode includes a GPIB device such as a digital multimeter connected to an IBM PC serial port through a GPIB 232CV A as shown in Figure 3 2 Serial Cable Sood oo
22. GPIB GPIB 232CV A User Manual IEEE 488 RS 232 Converter b f NATIONAL November 1999 Edition y INSTRUMENTS Part Number 370905A 01 Worldwide Technical Support and Product Information www ni com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 794 0100 Worldwide Offices Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 00 20 Brazil 011 284 5011 Canada Calgary 403 274 9391 Canada Ontario 905 785 0085 Canada Qu bec 514 694 8521 China 0755 3904939 Denmark 45 76 26 00 Finland 09 725 725 11 France 01 48 14 24 24 Germany 089 741 31 30 Greece 30 1 42 96 427 Hong Kong 2645 3186 India 91805275406 Israel 03 6120092 Italy 02 413091 Japan 03 5472 2970 Korea 02 596 7456 Mexico D F 5 280 7625 Mexico Monterrey 8 357 7695 Netherlands 0348 433466 Norway 32 27 73 00 Poland 48 22 528 94 06 Portugal 351 1 726 9011 Singapore 2265886 Spain 91 640 0085 Sweden 08 587 895 00 Switzerland 056 200 51 51 Taiwan 02 2377 1200 United Kingdom 01635 523545 For further support information see the Technical Support Resources appendix To comment on the documentation send e mail to techpubs ni com Copyright 1992 1999 National Instruments Corporation All rights reserved Important Information Warranty The GPIB 232CV A is warranted against defects in materials and workmanship for a period of two years from the date of shipment as evi
23. HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED SYSTEM FAILURES ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS INCLUDING THE RISK OF BODILY INJURY AND DEATH SHOULD NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE TO AVOID DAMAGE INJURY OR DEATH THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES INCLUDING BUT NOT LIMITED TO BACK UP OR SHUT DOWN MECHANISMS BECAUSE EACH END USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL INSTRUMENTS THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION Compliance FCC Canada Radio Frequency Interference Compliance Determining FCC Class The Federal Communications Commission FCC has rules to protect wireless communications from interference The FCC places dig
24. ON This mode is useful if your device is intended only to receive data In the example given in the CR or LF Termination Mode section of this chapter you could use the no swap mode to talk to the plotter if you never needed to obtain status information from it By adding a semicolon after the double quotation mark at the end of line 20 as shown below you suppress the CR Since you cannot readdress in no swap mode the CR is not needed to obtain status as it was in the previous example 10 OPEN COM1 9600 n 8 1 AS 1 Assumes GPIB 232CV A is at 9600 baud no parity 8 data bits 1 stop bit 20 PRINT 1 1000 1000 Plot absolute to 1000 1000 3 10 WWW ni com Chapter 3 Operation of the GPIB 232CV A 30 PRINT 1 cil100 Draw circle with radius of 100 units Data Buffering and Handshaking Schemes Two protection mechanisms are used to ensure that the GPIB 232CV A does not lose incoming serial data data buffering and handshaking The GPIB 232CV A has an internal RAM buffer that stores incoming serial data until it can output the data to the GPIB port The size of this RAM buffer determines how much serial data the GPIB 232CV A can accept before the buffer is completely full When its RAM buffer is nearly full the GPIB 232CV A can handshake with the serial host to stop data transmission When the buffer is almost empty the GPIB 232CV A can again handshake with the serial host to start da
25. RTS 7 to 7 7 to 4 CTS to CTS 8 to 8 8 to 5 The connections must be implemented National Instruments Corporation B 3 GPIB 232CV A User Manual Appendix Interfacing to a Serial Device Figure B 2 shows a properly configured 9 pin DTE to 9 pin DCE cable including the hardware handshake lines RTS CTS and DTR With this configuration the GPIB 232CV A can function properly handshake on buffer full conditions Figure B 3 shows an equivalent 9 pin DTE to 25 pin DCE cable configuration GPIB 232CV A Serial Device 9 pin DTE 9 pin DCE Figure B 2 Cable Configuration for 9 pin DTE to 9 pin DCE with Handshaking J T 0888898 GPIB 232CV A 9 0000 MMEMH Serial Device 25 pin DCE Figure B 3 Cable Configuration for 9 pin DTE to 25 pin DCE with Handshaking Interfacing the GPIB 232CV A to a DCE without Handshaking If your serial device does not require or use the hardware handshaking protocol used by the GPIB 232CV A you have two options e Use a minimum configuration cable which does not support hardware handshaking and use XON XOFF software handshaking if necessary To create a minimum configuration cable connect the signals shown in bold italics in Table B 2 GPIB 232CV A User Manual B 4 WWW ni com Appendix Interfacing to a Serial Device e Wire a custom cable that properly interfaces th
26. amount of GPIB data is expected to be sent to the GPIB 232CV A it would be advantageous to use the small 256 byte serial port buffer size if possible Then the majority of RAM is used as the GPIB buffer The larger serial buffer size is a means of capturing a larger percentage of the total RAM space for serial input use Regardless of the buffer size you choose serial data is not lost because the GPIB 232CV A implements a hardware handshake scheme and if selected the XON XOFF software handshake scheme The variable buffer size is a means of optimizing the GPIB 232CV A for your application Using the SRQ Feature GPIB 232CV A User Manual The GPIB bus performance might slow down if the Controller is constantly waiting for the GPIB 232CV A to send or receive data With SRQ enabled the bus can be used by other devices until the GPIB 232CV A requests service asserts SRQ When the GPIB 232CV A asserts SRQ the Controller serial polls the GPIB 232CV A to determine what type of service it needs After it is serial polled the GPIB 232CV A unasserts SRQ You can enable the SRQ feature by setting switch 6 of SW1 to the ON position 3 4 www ni com Chapter 3 Operation of the GPIB 232CV A Conditions That Cause SRQ to be Asserted If SRQ is enabled the GPIB 232CV A asserts the SRQ signal on two conditions e When the GPIB 232CV A receives serial data that it needs to pass on to the GPIB port e When the GPIB input buffer becomes empty
27. bles Table 1 1 EED D SCftptOlS ertet coe cete ves oii d edet ioco 1 4 Table 2 1 Configuration Parameters for SW1 Switches through 5 2 2 Table 2 2 Configuration Parameters for SW1 Switches 6 and 7 2 4 Table 2 3 Configuration Parameters for SW1 Switch 8 2 4 Table 2 4 Configuration Parameters for SW2 Switches through 3 2 5 Table 2 5 Configuration Parameters for SW2 Switches 4 through 8 2 6 Table 2 6 National Instruments Null Modem Serial Cables 2 7 Table B 1 RS 232 Serial Port Signal Configuration sees B 2 Table B 2 Cable Wiring Scheme for GPIB 232CV A DTE to Serial Device i eene eom Rene B 3 Table B 3 Cable Wiring Scheme for GPIB 232CV A DTE to senal Device DTE Sy i ala aon eene B 6 National Instruments Corporation ix GPIB 232CV A User Manual About This Manual Conventions The GPIB 232CV A User Manual describes the features functions and operation of the GPIB 232CV A This manual assumes that you have a general knowledge of RS 232 serial communications and the General Purpose Interface Bus GPIB A bold IEEE 488 and IEEE 488 2 italic monospace RS 232 The following conventions appear in this manual This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a sy
28. ch implements all IEEE 488 interface functions The GPIB 232CV A microprocessor contains an integrated memory management unit a dynamic RAM controller a clock generator a programmable timer unit a full duplex UART Universal Asynchronous Receiver Transmitter and an interrupt controller National Instruments Corporation 1 1 GPIB 232CV A User Manual Chapter 1 Introduction What You Need to Get Started Before you install your GPIB hardware make sure you have all of the following items One of the following boxes which is included in your kit GPIB 232CV A 100 120 VAC GPIB 232CV A 220 240 VAC GPIB 232CV A DC If you have the GPIB 232CV A AC version one of the following power cords USS standard power Swiss power cord Australian power cord Universal European power cord North American power cord U K power cord If you have the GPIB 232CV A DC version one of the following 9 V wall mount power supply 100 120 VAC 9 V wall mount power supply 220 240 VAC Type XI or X2 single shielded or double shielded GPIB cable 1 2 or 4 m which you can purchase from National Instruments Caution To meet FCC emission limits for this device you must use a Type X2 double shielded GPIB cable If you operate this equipment with a non shielded cable it may interfere with radio and television reception Optional Equipment You can order a 9 pin 2 m RS 232
29. configuration 3 3 technical support resources D 1 to D 2 WWW ni com timeout termination mode C mode configuration 3 8 to 3 9 top panel 1 4 to 1 5 illustration 1 4 LED descriptions table 1 4 to 1 5 Trigger GET command 3 3 TXD signal RS 232 port table B 2 National Instruments Corporation Index W Web support from National Instruments D 1 to D 2 online problem solving and diagnostic resources D 1 software related resources D 2 Worldwide technical support D 2 GPIB 232CV A User Manual
30. connecting to PC serial port example C 3 to C 4 IFC signal asserted in C mode 3 7 installation 2 6 to 2 8 connecting cables 2 7 powering on system and switching on GPIB 232CV A 2 8 National Instruments Corporation I 3 Index shutting down your system 2 6 verifying null model serial cable 2 7 L LED descriptions table 1 4 to 1 5 lt LF gt termination mode C mode configuration 3 9 to 3 10 LISTEN LED table 1 4 Listener D Mode configuration 3 3 Listen only mode purpose and use 3 6 switch settings figure 3 6 manual See documentation National Instruments Web support D 1 to D 2 no swap mode C mode configuration 3 10 to 3 11 null modem serial cable National Instruments null modem serial cables table 2 7 verifying during installation 2 7 0 online problem solving and diagnostic resources D 1 operation of GPIB 232CV A 3 1 to 3 12 C mode overview 3 7 to 3 11 choosing between D mode and C mode 3 1 to 3 2 D mode overview 3 3 to 3 6 data buffering and handshaking schemes 3 11 to 3 12 GPIB 232CV A User Manual Index P physical characteristics AC version A 2 DC version A 2 plotter GPIB connecting to PC serial port example C 3 to C 4 POWER LED table 1 4 print spooler high speed using GPIB 232CV A as example C 1 to C 3 problem solving and diagnostic resources online D 1 R READY LED checking during first power on 2 8 description table 1 4 rear
31. d it indicates that data transmission should be disabled Interfacing Serial Devices to the RS 232 Serial Port To interface other serial devices to the RS 232 serial port on the GPIB 232CV A first refer to the manual that came with your serial device to determine if the device is configured as a DTE or DCE Also determine from the manual how the control lines are used and whether they must be driven for the serial port to operate GPIB 232CV A User Manual B 2 WWW ni com Appendix Interfacing to a Serial Device Figure B 1 shows the location of the RS 232 connector DC Power Jack DC version only I JL a N NATIONAL oW E E gt GPIB 232C V A RS 232 IEEE 488 Controller Ns tnu MENS O LV S a C e o o o o o RS 232 Connector GPIB Connector Figure B 1 Location of the RS 232 Connector Interfacing the GPIB 232CV A to a DCE with Handshaking A correctly configured DTE to DCE interface is wired straight across GPIB 232CV A TXD to DCE TXD GPIB 232CV A RXD to DCE RXD and so on as shown in Table B 2 Table B 2 Cable Wiring Scheme for GPIB 232CV A DTE to Serial Device DCE Standard Standard GPIB 232CV A Signal to DTE to DCE DTE to DCE DCE Serial Device Signal 9 pin 9 pin 9 pin 25 pin RXD to RXD 2 to 2 2 to 3 TXD to TXD 3 to 3 3 to 2 DTR to DTR 4 to 4 4 to 20 GND to GND 5 to 5 5 to 7 RTS to
32. denced by receipts or other documentation National Instruments will at its option repair or replace equipment that proves to be defective during the warranty period This warranty includes parts and labor The media on which you receive National Instruments software are warranted not to fail to execute programming instructions due to defects in materials and workmanship for a period of 90 days from date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period National Instruments does not warrant that the operation of the software shall be uninterrupted or error free A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty National Instruments believes that the information in this document is accurate The document has been carefully reviewed for technical accuracy In the event that technical or typographical errors exist National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition The reader should consult National Instrume
33. e GPIB 232CV A hardware handshaking protocol to the handshaking protocol of your serial device Minimum Configuration Cable The minimum configuration cable assumes that the DCE does not require external hardware handshaking The minimum configuration for a DTE 9 pin to DCE 9 pin cable is shown in Figure B 4 Figure B 5 shows an equivalent 9 pin to 25 pin cable GPIB 232CV A Serial Device 9 pin DTE 9 pin DCE Figure B 4 Minimum Configuration for 9 pin DTE to 9 pin DCE 09 GPIB 232CV A 9 pin DTE 0000000000 HEHHHUS UH a a a Serial Device 25 pin DCE Figure B 5 Minimum Configuration for 9 pin DTE to 25 pin DCE National Instruments Corporation B 5 GPIB 232CV A User Manual Appendix Interfacing to a Serial Device Custom Cables If your application requires a custom cable you can construct one if you have a thorough knowledge of the handshaking protocols involved Review the RS 232 characteristics of your serial device and build the cable to properly connect the handshake lines of the two devices Because the DTE to DCE connection is a straight across connection it often involves only connecting RTS to RTS CTS to CTS DTR to DTR and so on If the documentation for your serial device does not provide a thorough explanation of its handshaking protocol the ANSI EIA 232 C standard is good reference provided your device conforms to the RS 232 protocol Caution Altho
34. e named printer include decl h include lt stdio h gt main argc argv char argv char fname 16 filename int f prompt for file name if not provided if argc lt 1 printf Enter filename gets fname C 2 www ni com Appendix C Application Examples filename fname else filename 1 find device printer if f ibfind printer 0 fprintf stderr Can t find printer n exit 1 write file if ibwrtf f filename amp ERR fprintf stderr Can t open s n argv 1 exit 1 After the program is compiled and linked you can run it just like the DOS print routine Then as long as you are not sending an amount of data greater than the buffer size of the GPIB 232CV A the data transfer should complete in a few seconds Connecting a HP7475 GPIB Plotter to a PC Serial Port Many software packages provide printing and plotting utilities which use your computer s serial port If GPIB support is not specifically provided in the package you cannot communicate with a GPIB device By using the GPIB 232CV A you can avoid this situation because the GPIB 232CV A allows communication between the serial port and GPIB devices For example an IBM PC running AUTOCAD sends data to the plotter by transferring data through the computer s serial port It cannot send data to a GPIB plotter such as the HP7475 GPIB plotter Because AUTOCAD suppor
35. e the HP7475 serial plotter GPIB 232CV A User Manual C 4 WWW ni com Technical Support Resources This appendix describes the comprehensive resources available to you in the Technical Support section of the National Instruments Web site and provides technical support telephone numbers for you to use if you have trouble connecting to our Web site or if you do not have internet access NI Web Support To provide you with immediate answers and solutions 24 hours a day 365 days a year National Instruments maintains extensive online technical support resources They are available to you at no cost are updated daily and can be found in the Technical Support section of our Web site at www ni com support Online Problem Solving and Diagnostic Resources e KnowledgeBase A searchable database containing thousands of frequently asked questions FAQs and their corresponding answers or solutions including special sections devoted to our newest products The database is updated daily in response to new customer experiences and feedback e Troubleshooting Wizards Step by step guides lead you through common problems and answer questions about our entire product line Wizards include screen shots that illustrate the steps being described and provide detailed information ranging from simple getting started instructions to advanced topics e Product Manuals A comprehensive searchable library of the latest editions of National Instrumen
36. easonable control Copyright Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation Trademarks NAT4882 National Instruments NI 488 2 and ni com are trademarks of National Instruments Corporation Product and company names mentioned herein are trademarks or trade names of their respective companies WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS 1 NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN 2 IN ANY APPLICATION INCLUDING THE ABOVE RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY COMPUTER HARDWARE MALFUNCTIONS COMPUTER OPERATING SYSTEM SOFTWARE FITNESS FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION INSTALLATION ERRORS SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS
37. efault Switch Settings for 2 2 5 Figure3 1 Example of D Mode System 3 2 Figure 3 2 Example of C Mode System Setup esse 3 2 Figure 3 3 Mode System 2 nennen 3 3 Figure 3 4 Switch Settings for Listen Only Mode sese 3 6 Figure 3 5 Mode System Layout essere nennen 3 7 Figure 3 6 Timeout Termination Mode Cycle sse 3 8 Figure B 1 Location of the RS 232 Connector B 3 Figure B 2 Cable Configuration for 9 pin DTE to 9 pin DCE With Handshaking Rer cobs exerce ente B 4 Figure B 3 Cable Configuration for 9 pin DTE to 25 pin DCE With Hand shaking uite ctore etl EISE E RE ERE totes B 4 Figure B 4 Minimum Configuration for 9 pin DTE to 9 pin DCE B 5 Figure B 5 Minimum Configuration for 9 pin DTE to 25 pin DCE B 5 Figure B 6 Cable Configuration for 9 pin DTE to 9 pin DTE with Hand shaking o iet reete EE ERE erede crede B 7 Figure B 7 Cable Configuration for 9 pin DTE to 25 pin DTE With Handsh king ccscescelivis trc e eere ence B 7 Figure B 8 Minimum Configuration for 9 pin DTE to 9 pin DTE B 8 Figure B 9 Minimum Configuration for 9 pin DTE to 25 pin DTE B 8 Figure C 1 Example of Print Spooler Setup sse C 2 Ta
38. ermination mode should be used for applications in which bidirectional communication is required and neither a CR nor lt LF gt character is used to signal the end of a command string to the GPIB device To select timeout termination mode set SW1 switches 6 and 7 to OFF Figure 3 6 shows the cycle of events in timeout termination mode aa GPIB Device Serial Seif Device DATA DATA Addressed Ee to Talk Serial Buffer Empty Receive Serial and No Serial Data Data Received for 300 msec Serial a GPIB Device Me DATA efl DATA Addressed Device HEHE to Listen Figure 3 6 Timeout Termination Mode Cycle GPIB 232CV A User Manual 3 8 WWW ni com Chapter 3 Operation of the GPIB 232CV A In timeout termination mode the GPIB 232CV A addresses the GPIB device to talk and any characters read from the GPIB port are passed along immediately to the serial port When a serial character is received by the GPIB 232CV A it immediately readdresses the GPIB device to listen and passes the character to it It remains in this mode until its serial input buffer becomes empty and no serial characters are received for 300 ms After this period of inactivity the GPIB 232CV A assumes that since no more serial data is being sent the device might have data that it needs to send back to the
39. icate Default settings appear in bold italics Table 2 1 Configuration Parameters for SW1 Switches 1 through 5 Switches 1 2 3 4 5 Indication OFF OFF OFF OFF OFF GPIB Primary Address 0 ON OFF OFF OFF OFF GPIB Primary Address 1 OFF ON OFF OFF OFF GPIB Primary Address 2 ON ON OFF OFF OFF GPIB Primary Address 3 OFF OFF ON OFF OFF GPIB Primary Address 4 2 2 www ni com Chapter 2 Configure and Install Your Hardware Table 2 1 Configuration Parameters for SW1 Switches 1 through 5 Continued Switches 1 2 3 4 5 Indication ON OFF ON OFF OFF GPIB Primary Address 5 OFF ON ON OFF OFF GPIB Primary Address 6 ON ON ON OFF OFF GPIB Primary Address 7 OFF OFF OFF ON OFF GPIB Primary Address 8 ON OFF OFF ON OFF GPIB Primary Address 9 OFF ON OFF ON OFF GPIB Primary Address 10 ON ON OFF ON OFF GPIB Primary Address 11 OFF OFF ON ON OFF GPIB Primary Address 12 ON OFF ON ON OFF GPIB Primary Address 13 OFF ON ON ON OFF GPIB Primary Address 14 ON ON ON ON OFF GPIB Primary Address 15 OFF OFF OFF OFF ON GPIB Primary Address 16 ON OFF OFF OFF ON GPIB Primary Address 17 OFF ON OFF OFF ON GPIB Primary Address 18 ON ON OFF OFF ON GPIB Primary Address 19 OFF OFF ON OFF ON GPIB Primary Address
40. ide information on local services You can access these Web sites from www ni com worldwide If you have trouble connecting to our Web site please contact your local National Instruments office or the source from which you purchased your National Instruments product s to obtain support For telephone support in the United States dial 512 795 8248 For telephone support outside the United States contact your local branch office Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 00 20 Brazil 011 284 5011 Canada Calgary 403 274 9391 Canada Ontario 905 785 0085 Canada Qu bec 514 694 8521 China 0755 3904939 Denmark 45 76 26 00 Finland 09 725 725 11 France 01 48 14 24 24 Germany 089 741 31 30 Greece 30 1 42 96 427 Hong Kong 2645 3186 India 91805275406 Israel 03 6120092 Italy 02 413091 Japan 03 5472 2970 Korea 02 596 7456 Mexico D F 5 280 7625 Mexico Monterrey 8 357 7695 Netherlands 0348 433466 Norway 32 27 73 00 Poland 48 22 528 94 06 Portugal 351 1 726 9011 Singapore 2265886 Spain 91 640 0085 Sweden 08 587 895 00 Switzerland 056 200 51 51 Taiwan 02 2377 1200 United Kingdom 01635 523545 D 2 WWW ni com Glossary Prefix Meaning Value u micro 10 6 m milli 10 3 k kilo 103 N degrees percent A amperes AC alternating current ANSI American National Standards Institute ASCII American Standards Code for Information Interchange ATN Attention C
41. ing speed of a computer computers must output data at a slow rate This forces you to wait for the data to be output or tolerate decreased performance if the data transfer occurs in the background One common solution to this problem is to use a print spooler to relieve the computer of this task With a GPIB 232CV A you can transfer data at GPIB rates instead of RS 232 rates The GPIB 232CV A uses a DMA Controller to input data from the GPIB port to the RAM buffer and can input GPIB data at rates up to 625 kbytes s Therefore the transfer rate is limited only by the rate at which the GPIB Talker can write data This example shows you how to connect and use your GPIB 232CV A as a high speed print spooler which returns control to you quickly so that you do not have to wait for the PC to finish printing or plotting a file The following example is based on the assumption that a National Instruments GPIB interface board such as the AT GPIB is installed in your computer and that you are familiar with the software configuration utility ibconf Use the following procedure to set up the system the first time 1 Use ibconf to configure the system so that a device named either printer or plotter is connected to the GPIB interface board Be sure to enable DMA transfers and to use high speed timing 2 Configure the GPIB 232CV A to operate in D mode with the small 256 bytes serial port buffer and SRQ disabled The serial buffer is set to the
42. ital electronics into two classes These classes are known as Class A for use in industrial commercial locations only or Class B for use in residential or commercial locations Depending on where it is operated this product could be subject to restrictions in the FCC rules In Canada the Department of Communications DOC of Industry Canada regulates wireless interference in much the same way Digital electronics emit weak signals during normal operation that can affect radio television or other wireless products By examining the product you purchased you can determine the FCC Class and therefore which of the two FCC DOC Warnings apply in the following sections Some products may not be labelled at all for FCC if so the reader should then assume these are Class A devices FCC Class A products only display a simple warning statement of one paragraph in length regarding interference and undesired operation Most of our products are FCC Class A The FCC rules have restrictions regarding the locations where FCC Class A products can be operated FCC Class B products display either a FCC ID code starting with the letters EXN Trado Nan Micdel Nunwber or the FCC Class B compliance mark that appears as shown here on the right FC Tested to Comply with FCC Standards The curious reader can consult the FCC web site http www fcc gov for more information FOR HOME OR OFFICE USE FCC DOC Warnings This equipment generates and uses
43. l Chapter 3 Operation of the GPIB 232CV A GPIB 232CV A User Manual Line 20 of the program outputs plotter commands to the serial port to both draw a line and obtain status Because neither a CR nor lt LF gt is sent between these commands the GPIB 232CV A keeps the GPIB plotter addressed to listen and sends all serial data received to the plotter Because the PRINT statement is not ended with a semicolon after the double quotation mark BASIC automatically sends a CR after the last character in the ASCII string is sent If the GPIB 232CV A is set up for CR termination the GPIB 232CV A then readdresses the plotter to talk so that its status can be output Line 30 inputs the status response from the plotter into the string variable RESPONSES Line 40 outputs the plotter command to the GPIB 232CV A to draw a circle As soon as the GPIB 232CV A receives the first character in this string it readdresses the plotter to listen and then sends these characters to it Notice that for this PRINT statement a semicolon is included after the last double quotation mark This means a CR is not sent Because no information is requested from the plotter there is no need to send a CR at the end of the string to address the plotter to talk No Swap Mode In no swap mode the GPIB 232CV A never readdresses a GPIB device after it has initially been addressed as a Listener To select no swap mode set SWI switches 6 and 7 to
44. leur du Canada Class B Federal Communications Commission This equipment has been tested and found to comply with the limits for a Class B digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures e Reorient or relocate the receiving antenna Increase the separation between the equipment and receiver Connect the equipment into an outlet on a circuit different from that to which the receiver is connected Consult the dealer or an experienced radio TV technician for help Canadian Department of Communications This Class B digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe B respecte toutes les exigences du R glement sur le mat riel brouilleur du Canada European Union Compliance to EEC Directives Readers in
45. ments Corporation 3 11 GPIB 232CV A User Manual Chapter 3 Operation of the GPIB 232CV A setup allows each device to monitor the RTS signal of the other device and to suspend transmission when necessary to prevent data loss Refer to Appendix B Interfacing to a Serial Device for more information on wiring schemes XON XOFF Software Handshaking If your serial device does not implement or recognize the hardware handshake scheme your cable does not support the necessary handshake lines or your application software requires XON XOFF handshaking you might need to enable the XON XOFF handshaking protocol by setting switch 8 of SW2 to ON This handshaking protocol performs the same function as the hardware handshake but does so by sending special control codes over the data lines instead of changing logic levels on dedicated control lines When you enable the XON XOFF protocol the GPIB 232CV A sends the XOFF character decimal 19 or lt Ctrl S gt before the internal buffer overflows When the GPIB 232CV A is able to start receiving characters again it sends the XON character decimal 17 or lt Ctrl Q gt Similarly if the GPIB 232CV A is transmitting data and receives the XOFF character it suspends transmission of any further data until it receives the XON character If you are transmitting binary data do not configure the GPIB 232CV A to use XON XOFF software handshaking Because the binary data could contain any binary sequence incl
46. nit and the ON OFF switch is in the ON position READY Indicates that the power on self test has successfully passed and the unit is ready to operate TALK Indicates that the GPIB 232CV A is configured as a GPIB Talker LISTEN Indicates that the GPIB 232CV A is configured as a GPIB Listener GPIB 232CV A User Manual 1 4 WWW ni com Chapter 1 Introduction Table 1 1 LED Descriptions Continued LED Indication BUSY Indicates that the GPIB 232CV A is currently accepting serial data Each serial character received toggles the status of the BUSY LED FULL Indicates that one of the GPIB 232CV A data buffers is full This is not an error condition but is merely a signal that bus performance may be reduced to the speed of the slower port Rear Panel The configuration switches are located on the rear panel of the GPIB 232CV A The power switch of the DC version is also located on the rear panel Figure 1 3 shows the rear panel of the GPIB 232CV A MODE BAUD RATE CONFIG DATA FORMAT GPIB ADDRESS HANDSHAKE Figure 1 3 GPIB 232CV A Rear Panel National Instruments Corporation 1 5 GPIB 232CV A User Manual Chapter 1 Introduction Side Panels The GPIB connector and the RS 232 connector are mounted on opposite side panels On the DC version the DC power jack is on the same end as the
47. nts if errors are suspected In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN NATIONAL INSTRUMENTS MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of National Instruments will apply regardless of the form of action whether in contract or tort including negligence Any action against National Instruments must be brought within one year after the cause of action accrues National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover damages defects malfunctions or service failures caused by owner s failure to follow the National Instruments installation operation or maintenance instructions owner s modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood accident actions of third parties or other events outside r
48. on the RS 232C standard contact Global Engineering Documents 7730 Carondelet Avenue Suite 4007 St Louis MO 63105 800 854 7179 National Instruments Corporation B 1 GPIB 232CV A User Manual Appendix Interfacing to a Serial Device RS 232 Port Overview The RS 232 serial port on the GPIB 232CV A uses a male 9 pin D Subminiature connector with a DTE interface configuration Table B 1 shows the signal lines supported on the GPIB 232CV A Table B 1 RS 232 Serial Port Signal Configuration Pin RS 232 Number Signal Description Code Function 2 RXD BB This signal carries serial data from the serial Receive Data device to the GPIB 232CV A 3 TXD BA This signal carries serial data from the Transmit Data GPIB 232CV A to the serial device 4 DTR CD This signal is asserted by the GPIB 232CV A to Data Terminal Ready signal that it has been powered on and is ready to operate 5 GND AB This signal establishes a reference point for all Ground interface voltages 7 RTS CA This signal is driven by the GPIB 232CV A Request to Send When asserted it indicates that the GPIB 232CV A is ready to accept serial data When unasserted it indicates that the GPIB 232CV A is no longer ready to accept serial data because the buffer is full 8 CTS CB This signal is sensed by the GPIB 232CV A Clear to Send When asserted it indicates that the serial device is ready to accept serial data When unasserte
49. ormance when large amounts of data are sent to the GPIB 232CV A enable the SRQ feature and send only data amounts up to but not exceeding the GPIB input buffer size The Controller can then unaddress the GPIB 232CV A to listen so that other devices can use the bus When the GPIB 232CV A is ready to receive more data it asserts the SRQ signal National Instruments Corporation 3 5 GPIB 232CV A User Manual Chapter 3 Operation of the GPIB 232CV A GPIB 232CV A Serial Poll Responses If the GPIB 232CV A is serial polled its response byte depends on the status of the internal data buffers as follows e Ifthe serial input buffer is empty bit 1 of the status byte is set to 1 e Ifthe serial input buffer is not empty bit 1 is set to 0 e Ifthe GPIB input buffer is empty bit O of the status byte is set to 1 e If the GPIB input buffer is not empty bit 0 is set to 0 In all cases bit 6 is set to 1 if the GPIB 232CV A is requesting service otherwise it is set to 0 GPIB 232CV A Operation in Listen Only Mode In listen only mode no addressing is required to make the GPIB 232CV A a GPIB Listener and it cannot be unaddressed to listen All data transferred on the GPIB is accepted by the GPIB 232CV A and output to the serial port even if the data was intended for another device This configuration can be used to monitor all GPIB data bus activity Notice that when the GPIB 232CV A is configured as a listen only device it cannot be serial
50. ormance with SRQ esee 3 5 GPIB 232CV A Serial Poll Responses eee 3 6 GPIB 232CV A Operation in Listen Only Mode sess 3 6 C Mode Overview grenier de OR He RERO ERR 3 7 Data Transfers in C Mode sinisesse rseson eesriie 3 7 Modes of Operation Within C Mode sese 3 8 Timeout Termination Mode sess 3 8 CR lt LF gt Termination Mode see 3 0 No Swap Mode tet entre ene eet ere 3 10 Data Buffering and Handshaking Schemes eee 3 11 Hardware Handshaking esses eene 3 11 XON XOFF Software Handshaking sess 3 12 Appendix A Specifications Appendix B Interfacing to a Serial Device Appendix C Application Examples Appendix D Technical Support Resources Glossary Index Figures Figure 1 1 GPIB 232CV A AC Front Panel essere 1 3 Figure 1 2 GPIB 232CV A Top Panel once eite 1 4 Figure 1 3 GPIB 232CV A Rear Panel eese 1 5 Figure 1 4 Location of the Connectors and the DC Power Jack 1 6 Figure 1 5 RS 232 Connector and Signal Designations esses 1 7 Figure 1 6 GPIB Connector and Signal Designations sees 1 8 GPIB 232CV A User Manual viii www ni com Contents Figure 2 1 Factory Default Switch Settings for SW 2 2 Figure 2 2 Factory D
51. ort C 3 to C 4 using GPIB 232CV A as high speed print spooler C 1 to C 3 ATTN signal assertion in D mode 3 3 buffer size for serial port choosing 3 4 BUSY LED table 1 5 C C mode configuration 3 7 to 3 11 choosing between D mode and C mode 3 1 to 3 2 Controller in Charge 3 7 CR or lt LF gt termination mode 3 9 to 3 10 data transfers 3 7 example of system setup figure 3 2 IFC assertion 3 7 modes of operation 3 8 to 3 11 no swap mode 3 10 to 3 11 REN assertion 3 7 system layout figure 3 7 timeout termination mode 3 8 to 3 9 when to use 3 2 cables connecting 2 7 configuration 2 1 to 2 6 factory configuration settings 2 1 location of switches on rear panel figure 1 5 operating at incorrect voltage caution 2 1 National Instruments Corporation parameters for SW1 switches CR or lt LF gt termination mode 3 9 to 3 10 default settings for SW1 figure 2 2 Listen only mode setting figure 3 6 parameters for SW1 switch 8 table 2 4 parameters for SW1 switches 1 through 5 table 2 2 to 2 4 parameters for SW1 switches 6 and 7 table 2 4 serial port parameters factory default switch settings figure 2 5 SW2 switches 1 through 3 table 2 5 to 2 6 SW2 switches 4 through 8 table 2 6 conventions used in manual xi CR or lt LF gt termination mode C mode configuration 3 9 to 3 10 CTS signal RS 232 port table B 2 D D mode configuration 3 3 to 3 6 ATN
52. panel 1 5 REN signal asserted in C mode 3 7 requirements for getting started 1 2 RS 232 serial port buffer size selection in D mode 3 4 configuration parameters factory default settings figure 2 5 SW2 switches 1 through 3 table 2 5 to 2 6 SW2 switches 4 through 8 table 2 6 interfacing serial devices B 2 to B 9 location of RS 232 connector figure B 3 to DCE with handshaking B 3 to B 4 to DCE without handshaking B 4 to B 6 to DTE with handshaking B 6 to B 7 to DTE without handshaking B 7 to B 9 overview 1 7 GPIB 232CV A User Manual 1 4 RS 232C standard for B 1 signal configuration table B 2 signals supported figure 1 7 RTS signal RS 232 port table B 2 RXD signal RS 232 port table B 2 S SDC Selected Device Clear command 3 3 serial cable null modem 2 7 serial poll response of GPIB 232CV A 3 6 serial port See RS 232 serial port side panels 1 6 to 1 8 GPIB connector 1 8 location of connectors and DC power jack figure 1 6 RS 232 connector 1 7 software related resources D 2 specifications electrical characteristics AC version 1 DC version A 1 environment characteristics AC version 1 to 2 DC version A 2 physical characteristics AC version A 2 DC version A 2 SRQ feature conditions causing assertion of SRQ 3 5 enabling 3 4 maximizing performance with SRQ 3 5 purpose and use 3 4 switches See configuration T TALK LED table 1 4 Talker D Mode
53. polled The GPIB primary address for the GPIB 232CV A is specified by switches 1 through 5 of the DIP switch SW1 If GPIB address switches through 5 are all set to ON the GPIB 232CV A is configured as a listen only device Figure 3 4 shows the switch settings for listen only mode MODE CONFIG GPIB ADDRESS 4 1 12345678 SW1 Figure 3 4 Switch Settings for Listen Only Mode GPIB 232CV A User Manual 3 6 WWW ni com Chapter 3 Operation of the GPIB 232CV A C Mode Overview In C mode the GPIB 232CV A anda serial device together act as the GPIB System Controller Figure 3 5 shows the C mode system layout GPIB Controller VASA f Serial N suy GPIB Device Lee 71 Device GPIB 232CV A Figure 3 5 C Mode System Layout When you turn the power on with the GPIB 232CV A in C mode the GPIB 232CV A asserts IFC for 500 us and addresses the instruments to listen On a GPIB system asserting IFC for at least 100 us initializes the GPIB and causes the System Controller to become Controller In Charge CIC After the GPIB 232CV A becomes CIC it sends out the GPIB listen address indicated by SW1 switches 1 through 5 If switches 1 through 5 are all ON no addressing is performed This configuration is useful if you are talking to a listen onl
54. r on all devices If you have an AC version use the front panel rocker switch to power on your GPIB 232CV A If you have a DC version use the power switch on the rear panel to power on your GPIB 232CV A The POWER LED indicator should come on immediately The READY LED indicator should come on after the GPIB 232CV A has passed its power on self test indicating the unit is ready for operation If the READY LED does not come on within seven seconds after the unit is powered on recheck all connections and switch settings and retry the power on sequence If the READY LED still does not come on contact National Instruments for technical support 2 8 WWW ni com Operation of the GPIB 232CV A This chapter describes how to choose between D mode configuration and C mode configuration and contains information about operating the GPIB 232CV A in D mode or C mode data buffering and handshaking schemes The following terms are specific to the sections in this chapter e lt A suffix after a mnemonic indicates active low e A bold mnemonic indicates that it is a signal name or a top panel LED indicator e CR is the symbol for the Carriage Return character hex OD e lt LF gt is the symbol for the Linefeed character hex Choosing Between D Mode and C Mode Configuration The GPIB 232CV A can be configured either as a GPIB device that is addressed to talk or listen by a GPIB Controller on the bus D mode or as a GPIB
55. smallest size to allow the GPIB port which is the data source to use the majority of RAM Set the GPIB address to the same address National Instruments Corporation C 1 GPIB 232CV A User Manual Appendix C Application Examples GPIB 232CV A User Manual assigned to the device plotter or printer in ibconf Configure the serial port parameters to match those of the printer or plotter 3 Connect the GPIB cable from the PC to the GPIB 232CV A and connect the serial cable from the GPIB 232CV A to the printer or plotter The system should resemble the diagram in Figure C 1 Serial Cable GPIB Cable SEES p c ooooco N H Printer GPIB 232CV A PC Figure C 1 Example of Print Spooler Setup 4 Provide a means to transfer data to the printer or plotter easily via the GPIB port on your PC You can simply redirect the serial output to the GPIB device as explained in the NI 488 2 Software Reference Manual for MS DOS but the overhead associated with the DOS calls makes this method inherently slow The fastest way to transfer data to the GPIB port is to write a small program that executes a GPIB file write The following program is an example of how to do a GPIB file write in the C programming language You can use other languages in the same way FASTPRINT dumps specified data file out GPIB to devic
56. stem crash Bold text denotes items that you must select or click on in the software such as menu items and dialog box options Bold text also denotes parameter names IEEE 488 and IEEE 486 2 refer to the ANSI IEEE Standard 488 1 1987 and the ANSI IEEE Standard 488 2 1992 respectively which define the GPIB Italic text denotes variables emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts RS 232 refers to the ANSI EIA 232 C standard National Instruments Corporation Xi GPIB 232CV A User Manual About This Manual Related Documentation The following documents contain information that you might find helpful as you read this manual e ANSI EIA 232 C Interface Between Data Terminal Equipment and Data Circuit Terminating Equipment Employing Serial Binary Data Interchange e ANSI IEEE Standard 488 1 1987 IEEE Standard Digital Interface for Programmable Instrumentation ANSI IEEE Standard 488 2 1992 IEEE Standard Codes Formats Protocols and Common Commands GPI
57. ta transmission The GPIB 232CV A is capable of using both the XON XOFF software handshaking and the hardware handshaking protocols Hardware Handshaking The hardware handshake function is always active during RS 232 transfers and uses the Request to Send RTS and Clear to Send CTS signal lines When the GPIB 232CV A is ready to accept serial data it asserts the RTS line This signal remains asserted until the data buffer of the GPIB 232CV A is almost full At this point the GPIB 232CV A unasserts the RTS line signaling to the serial host that the GPIB 232CV A is no longer ready to accept data The serial host should monitor the RTS line and suspend data transmission whenever the RTS line becomes unasserted The GPIB 232CV A asserts RTS when it is again ready to receive serial data The GPIB 232CV A is also able to suspend transmission when the serial device is no longer ready to accept data The GPIB 232CV A is configured to immediately stop transmission of serial data when CTS becomes unasserted The GPIB 232CV A resumes transmission as soon as CTS is reasserted Because most serial devices use the same form of hardware handshaking as the GPIB 232CV A you can achieve bidirectional flow control by using a serial cable that connects the RTS signal of the GPIB 232CV A to the CTS signal of the serial device In addition the RTS signal of the serial device should be connected to the CTS signal of the GPIB 232CV A This National Instru
58. ts hardware and software product manuals e Hardware Reference Database A searchable database containing brief hardware descriptions mechanical drawings and helpful images of jumper settings and connector pinouts e Application Notes A library with more than 100 short papers addressing specific topics such as creating and calling DLLs developing your own instrument driver software and porting applications between platforms and operating systems National Instruments Corporation D 1 GPIB 232CV A User Manual Appendix D Technical Support Resources Software Related Resources Instrument Driver Network A library with hundreds of instrument drivers for control of standalone instruments via GPIB VXI or serial interfaces You also can submit a request for a particular instrument driver if it does not already appear in the library e Example Programs Database A database with numerous non shipping example programs for National Instruments programming environments You can use them to complement the example programs that are already included with National Instruments products e Software Library A library with updates and patches to application software links to the latest versions of driver software for National Instruments hardware products and utility routines Worldwide Support GPIB 232CV A User Manual National Instruments has offices located around the globe Many branch offices maintain a Web site to prov
59. ts the HP7475 serial plotter you can use the GPIB 232CV A to convert the serial data from AUTOCAD into GPIB data for the plotter The GPIB 232CV A automatically takes care of the GPIB addressing and transparently converts the data from one format to the other To use the GPIB 232CV A in this way follow these steps 1 Start AUTOCAD and select Configure AUTOCAD from the Main Menu Select the HP7475 plotter and configure the rest of the operating parameters that you need 2 Configure your GPIB 232CV A Set it to operate in C mode with timeout termination Set the GPIB address of the plotter using the National Instruments Corporation C 3 GPIB 232CV A User Manual Appendix C Application Examples GPIB 232CV A configuration switches Set the serial port parameters to XON XOFF disabled 9600 baud 7 data bits 1 stop bit and even parity 3 Poweron the plotter then power on the GPIB 232CV A When the GPIB 232CV A is powered on it addresses the GPIB plotter Any data sent to the serial port by AUTOCAD is received by the GPIB 232CV A and stored in its internal buffer The GPIB 232CV A transfers the data to the plotter over the GPIB connection as fast as the plotter can receive it Because the GPIB 232CV A provides a data buffer that spools the data as it is sent the PC will be able to send data at serial rates instead of plotter rates Therefore your data is output to the GPIB plotter by AUTOCAD in less time than it would have taken to us
60. uding decimal 19 lt Ctrl S gt or decimal 17 lt Ctrl Q gt the GPIB 232CV A would not be able to distinguish between data values or handshake control codes If handshaking were enabled the GPIB 232CV A would handshake erratically GPIB 232CV A User Manual 3 12 www ni com Specifications This appendix lists the electrical environmental and physical characteristics of the GPIB 232CV A Electrical Characteristics AC Version Power supply unit 100 120 VAC 10 50 60 Hz 220 240 V AC E10 50 60 Hz Current requirement 100 120 55 mA 220 240 45 mA Fuse rating and type 100 120 VAQC iet tete 300 mA UL CSA approved 220 240 500 mA approved DC Version Power supply unit 50 60 Hz input 9 VDC at 1 A output Wall mount type 100 120 VAC 1096 Desktop type 220 240 VAC 10 DC inp t eterne 5 to 13 regulated Current ue DAHER 700 mA minimum Environmental Characteristics AC Version Operating 10 to 40 C Storage temperature 0 to 70 C National Instruments Corporation A 1 GPIB 232CV A User Manual Appendix Specifications DC Version Operating temperature Storage temperat
61. ugh handshaking might not be required it is best to use some form of handshaking to prevent loss of data Interfacing the GPIB 232CV A to a DTE with Handshaking GPIB 232CV A User Manual For serial devices set up as DTEs you must wire a DTE to DTE interface cable commonly known as a null modem cable The cable allows the GPIB 232CV A to act as though it is communicating with a DCE but it swaps the appropriate pins to achieve a DTE pinout This wiring configuration is shown in Table B 3 Table B 3 Cable Wiring Scheme for GPIB 232CV A DTE to Serial Device DTE Standard Standard GPIB 232CV A Signal to DTE to DTE DTE to DTE DTE Serial Device Signal 9 pin 9 pin 9 pin 25 pin to TXD 2 to 3 2 to 2 TXD to RXD 3 to 2 3 to 3 DTR to DSR 4 to 6 4 to 6 GND to GND 5 to 5 5 to 7 RTS to CTS 7 to 8 7 to 5 CTS to RTS 8 to 7 8 to 4 1 The connections must be implemented Figure B 6 shows a typical 9 pin to 9 pin null modem cable with the RTS CTS and DTR handshake lines implemented Figure B 7 shows an equivalent 9 pin DTE to 25 pin DTE cable configuration B 6 WWW ni com Appendix Interfacing to a Serial Device The cable configuration in Figure B 6 allows you to connect to the 9 pin serial port of a personal computer The cable in Figure B 7 shows how to connect to the 25 pin serial port of a personal computer GPIB 232CV A Serial Device 9 pin DTE 9 pin
62. uration switches For information on choosing the mode of operation refer to Choosing Between D Mode and C Mode Configuration in Chapter 3 Operation of the GPIB 232CV A Chapter 3 also contains information about choosing whether or not to use other available features National Instruments Corporation 2 1 GPIB 232CV A User Manual Chapter 2 Configure and Install Your Hardware If you are already using the GPIB 232CV A and decide to change its operating characteristics you must first shut down your system and then continue with the following steps Configure the GPIB 232CV A Parameters GPIB 232CV A User Manual You can use the DIP switches on the rear panel see Figure 1 1 GPIB 232CV A AC Front Panel and Figure 1 4 Location of the Connectors and the DC Power Jack to configure the GPIB 232CV A Figure 2 1 shows the factory default setting for SW1 MODE CONFIG GPIB ADDRESS 4 12345678 SW1 Figure 2 1 Factory Default Switch Settings for SW1 In Figure 2 1 switches 1 through 5 are ON OFF ON OFF and OFF respectively indicating a GPIB primary address of 5 Switches 6 and 7 are in the OFF position indicating that SRQ is disabled and the small serial buffer is used Switch 8 is in the OFF position indicating that the unit is configured to operate in D mode Tables 2 1 2 2 and 2 3 show the possible configurations of SW1 and what the configurations ind
63. ure Relative humidity Physical Characteristics AC Version Case size DC Version Case size GPIB 232CV A User Manual A 2 10 to 95 noncondensing FCC Class A Verified 10 to 40 C 0 to 70 C 10 to 95 noncondensing FCC Class B Certified 118 1 by 76 2 by 44 2 mm 4 65 by 3 0 by 1 74 in All metal enclosure 340 g 12 oz 118 1 by 76 2 by 28 2 mm 4 65 by 3 0 by 1 11 in metal enclosure 198 g 7 oz WWW ni com Interfacing to a Serial Device This appendix describes the RS 232 serial port on the GPIB 232CV A and explains how to interface a DCE or DTE serial device to the RS 232 serial port The GPIB 232CV A transfers serial data using the electrical signals mechanical connections data format and control protocols defined in the RS 232C standard The RS 232 port on the GPIB 232CV A is an asynchronous serial communication link to a serial peripheral device RS 232C Standard The RS 232C standard international standard CCITT V 24 was formulated in 1969 largely from the efforts of the Electronic Industries Association EIA and Bell Laboratories The standard describes the electrical specifications and arrangement of control and data signals on both sides of a serial communications interface Its original intent was to interface terminals to modems Many manufacturers of computers and instruments have adopted the standard for their serial communications needs For more information
64. y device that does not require addressing The GPIB 232CV A always asserts REN when addressing other devices Data Transfers in C Mode All incoming serial data to the GPIB 232CV A is stored in an internal data buffer until it is accepted by the GPIB device All GPIB data sent to the GPIB 232CV A is passed immediately to the serial port without being buffered You can send data to your serial port as if you had a serial device connected to it The data is converted and sent to the GPIB instrument When the instrument has data to send back the GPIB 232CV A addresses the instrument to talk and passes all received data to the RS 232 port National Instruments Corporation 3 7 GPIB 232CV A User Manual Chapter 3 Operation of the GPIB 232CV A Modes of Operation Within C Mode Four different modes of operation are available within C mode to define when the GPIB device is addressed to talk or listen These modes are as follows Timeout termination e CR termination e lt termination e No swap In every mode the device is addressed to listen after the GPIB 232CV A becomes CIC and all data received via the serial port is buffered and passed along to the device The four modes of operation define the point at which the GPIB device is unaddressed to listen and addressed to talk so that data can be sent from the device to the GPIB 232CV A You can select these modes using SW1 switches 6 and 7 Timeout Termination Mode Timeout t

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