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NI-488.2 User Manual for Windows

1. Mnemonic Bit Position Hex Value Type Description ERR 15 8000 dev brd NI 488 2 error TIMO 14 4000 dev brd Time limit exceeded END 13 2000 dev brd END or EOS detected SRQI 12 1000 brd SRQ interrupt received RQS 11 800 dev Device requesting service CMPL 8 100 dev brd T O completed LOK 7 80 brd Lockout State REM 6 40 brd Remote State CIC 5 20 brd Controller In Charge ATN 4 10 brd Attention is asserted TACS 3 8 brd Talker LACS 2 4 brd Listener DTAS 1 2 brd Device Trigger State DCAS 0 1 brd Device Clear State National Instruments Corporation B 1 NI 488 2 User Manual for Windows Appendix B Status Word Conditions ERR dev brd ERR is set in the status word following any call that results in an error You can determine the particular error by examining the error variable iberr Appendix C Error Codes and Solutions describes error codes that are recorded in iberr along with possible solutions ERR is cleared following any call that does not result in an error TIMO dev brd TIMO indicates that the timeout period has expired TIMO is set in the status word following any synchronous I O functions for example ibcmd ibrd ibwrt Receive Send and Sendcmds if the timeout period expires before the I O operation has completed TIMO is also set in the status word following an ibwait or ibnotify call if the TIMO bit is set in the mask parameter and the timeout period expires before any other specif
2. DeviceError TRUE NI 488 2 User Manual for Windows 7 8 ni com Chapter 7 NI 488 2 Programming Techniques return 0 else return RQS Writing Multithreaded Win32 NI 488 2 Applications If you are writing a multithreaded NI 488 2 application and you plan to make all of your NI 488 2 calls from a single thread you can safely continue to use the traditional NI 488 2 global variables ibsta iberr ibent ibent1 The NI 488 2 global variables are defined on a per process basis so each process accesses its own copy of the NI 488 2 globals If you are writing a multithreaded NI 488 2 application and you plan to make NI 488 2 calls from more than a single thread you cannot safely continue to use the traditional NI 488 2 global variables without some form of synchronization for example a semaphore To understand why refer to the following example Assume that a process has two separate threads that make NI 488 2 calls thread 1 and thread 2 Just as thread 1 is about to examine one of the NI 488 2 globals it gets preempted and thread 2 is allowed to run Thread 2 proceeds to make several NI 488 2 calls that automatically update the NI 488 2 globals Later when thread 1 is allowed to run the NI 488 2 global that it is ready to examine is no longer in a known state and its value is no longer reliable The previous example illustrates a well known multithreading problem It is unsafe to access process global variabl
3. gpib 32 d11 exports pointers to the global variables and all of the NI 488 2 calls Pointers to the global variables ibsta iberr ibcnt and ibcnt1 are accessible through these exported variables int user_ibsta int user_iberr int user_ibcnt long user_ibcnt1l Except for the functions ibbna ibfind ibrdf and ibwrtf all the NI 488 2 call names are exported from gpib 32 d11 Thus to use direct entry to access a particular function and to get a pointer to the National Instruments Corporation 3 13 NI 488 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application exported function you just need to call Get ProcAddress passing the name of the function as a parameter For more information about the parameters to use when you invoke the function refer to the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual The functions ibbna ibfind ibrdf and ibwrtf all require an argument that is a name ibbna requires an interface name ibfind requires an interface or device name and ibrdf and ibwrtf require a file name Because Windows 2000 NT supports both normal 8 bit and Unicode 16 bit characters gpib 32 d11 exports both normal and Unicode versions of these functions Because Windows Me 98 95 does not support 16 bit wide characters use only the 8 bit ASCII versions named ibbnaA ibfindA ibrdfA and ibwrt fA The
4. A GPIB line that signals either the last byte of a data message END or the parallel poll Identify IDY message NI 488 2 User Manual for Windows G 2 ni com EOS or EOS Byte EOT ESB FIFO GET GPIB GPIB address GPIB board GTL H handshake National Instruments Corporation G 3 Glossary A 7 or 8 bit end of string character that is sent as the last byte of a data message End of transmission The Event Status bit Part of the IEEE 488 2 defined status byte which is received from a device responding to a serial poll First in first out Group Execute Trigger The GPIB command used to trigger a device or internal function of an addressed Listener General Purpose Interface Bus is the common name for the communications interface system defined in ANSI IEEE Standard 488 1 1987 and ANSI TEEE Standard 488 2 1992 The address of a device on the GPIB composed of a primary address MLA and MTA and perhaps a secondary address MSA The GPIB board has both a GPIB address and an I O address Refers to the National Instruments family of GPIB interfaces Go To Local The GPIB command used to place an addressed Listener in local front panel control mode The mechanism used to transfer bytes from the source handshake function of one device to the acceptor handshake function of another device DAV NRFD and NDAC three GPIB lines are used in an interlocked fashion to signal the phases of the transfer
5. NOADDR PPollUnconfig 0 AddressList National Instruments Corporation 7 19 NI 488 2 User Manual for Windows GPIB Basics The ANSI IEEE Standard 488 1 1987 also known as General Purpose Interface Bus GPIB describes a standard interface for communication between instruments and controllers from various vendors It contains information about electrical mechanical and functional specifications GPIB is a digital 8 bit parallel communications interface with data transfer rates of 1 Mbyte s and higher using a three wire handshake The bus supports one System Controller usually a computer and up to 14 additional instruments The ANSI IEEE Standard 488 2 1992 extends IEEE 488 1 by defining a bus communication protocol a common set of data codes and formats and a generic set of common device commands Talkers Listeners and Controllers GPIB devices can be Talkers Listeners or Controllers A Talker sends out data messages Listeners receive data messages The Controller usually a computer manages the flow of information on the bus It defines the communication links and sends GPIB commands to devices Some devices are capable of playing more than one role A digital voltmeter for example can be a Talker and a Listener If your system has a National Instruments GPIB interface and software installed it can function as a Talker Listener and Controller Controller In Charge and System Controller You can ha
6. HS488 National Instruments NI 488 2 ni ccom and TNT4882 C 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 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 DEAT
7. Piberr National Instruments Corporation 3 15 NI 488 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application long Pibcntl static int __stdcall Pibdev int ud int pad int sad int tmo int eot int eos static int __stdcall Pibonl int ud int v Pibsta int GetProcAddress Gpib32Lib LPCSTR user_ibsta Piberr int GetProcAddress Gpib32Lib LPCSTR user_iberr Pibentl long GetProcAddress Gpib32Lib LPCSTR user_ibent Pibdev int __stdcall int int int int int int Get ProcAddress Gpib32Lib LPCSTR ibdev Pibonl int __stdcall int int Get ProcAddress Gpib32Lib LPCSTR ibonl If Get ProcAddress fails it returns a NULL pointer The following code fragment shows you how to verify that none of the calls to Get ProcAddress failed if Pibsta NULL Piberr NULL Pibentl NULL Pibdev NULL Pibonl NULL Free the GPIB library FreeLibrary Gpib32Lib printf GetProcAddress failed Your Win32 application needs to dereference the pointer to access either the status variables or function The following code shows you how to call a function and access the status variable from within your application dvm Pibdev 0 1 0 T10s 1 0 if Pibsta amp ERR printf Call failed NI 488 2 User Manual for Windows 3 16 ni com Chapter 3 Developing Your NI 488 2
8. PnP interface 22 The GPIB interface is disabled To enable the GPIB interface check the appropriate configuration checkbox in the Device Usage section of the General tab 24 The GPIB interface is not present or the Select the interface in the Device Manager Device Manager is unaware that the and click on the Remove button Next click GPIB interface is present on the Refresh button At this point the system rescans the installed hardware and the GPIB interface should show up without any problems If the problem persists contact National Instruments 27 Windows was unable to assign the GPIB Free up system resources by disabling other interface any resources unnecessary hardware so that enough resources are available for the GPIB interface National Instruments Corporation D 3 NI 488 2 User Manual for Windows Appendix D Windows Me 98 95 Troubleshooting and Common Questions Enabling Interrupts In Windows Me 98 95 you can use your GPIB interface without interrupts but the NI 488 2 software performance is significantly slower without interrupts For example transfer sizes between 1 and 10 bytes transfer at a rate of only 2 of the transfer rate with enabled interrupts As the transfer size increases the performance degradation decreases slightly but it remains a significant problem for all transfers under 1 Mbyte If you find the diminished performance unacceptable complete the followin
9. SEND DATA 9L if ibsta amp ERR printf unable to write to device n return 0 set up the asynchronous event notification on RQS ibnotify ud RQS MyCallback NULL NI 488 2 User Manual for Windows 7 6 ni com Chapter 7 NI 488 2 Programming Techniques if ibsta amp ERR printf ibnotify call failed n return 0 while ReadingsTaken lt 1000 amp amp DeviceError Your application does useful work here For example it might process the device readings or do any other useful work disable notification ibnotify ud 0 NULL NULL Call the ibonl function to disable the hardware and software ibonl ud 0 return 1 int _stdcall MyCallback int LocalUd int LocalIbsta int LocallIberr long LocalIbcntl void RefData char SpollByte char ReadBuffer 40 If the ERR bit is set in LocalIbsta then print an error message and return if LocalIbsta amp ERR printf GPIB error d has occurred No more callbacks n LocallIberr DeviceError TRUE return 0 Read the serial poll byte from the device If the ERR bit is set in ibsta then print an error message and return LocalIbsta ibrsp LocalUd amp SpollByte if LocalIbsta amp ERR printf ibrsp failed No more callbacks n DeviceError TRUE return 0 Tf the returned status byte equals the expected response then the device has valid data to send otherwise it has a
10. amp Automation Explorer and select Scan for Instruments After Explorer scans your interface it displays your instrument address in the right window pane The instrument shown in Figure 6 1 has a primary address of 1 and no secondary address Description BS GPIB Interface Number 0 Instrument0 Primary ddress 1 FLUKE 45 4790173 1 6 D1 0 Figure 6 1 Instrument Address in Measurement amp Automation Explorer NI 488 2 User Manual for Windows 6 2 ni com National Instruments Corporation Chapter 6 Interactive Control Utility After you successfully complete ibdev you have a ud prompt The new prompt udo represents a device level handle that you can use for further NI 488 2 calls To clear the device use ibclr as follows ud0 ibclr 0100 cmp1 To write data to the device use ibwrt Make sure that you refer to the documentation that came with your GPIB instrument for recognized command messages ud0 ibwrt enter string 0100 count 5 IDN cmp1 Or equivalently udO ibwrt IDN 0100 cmp1 count 5 To read data from your device use ibrd The data that is read from the instrument is displayed For example to read 29 bytes enter the following ud0 ibrd enter byte count 29 0100 cmp1 count 29 46 4C 55 4B 45 2C 20 34 FLUKE 4 35 2C 20 34 37 39 30 31 5 47901 37 33 2C 20 31 2E 36 20 73 1 6 44 31 2E 30 OA D 10 Or equivalently ud0 ibrd 29 0100 cmp1 count 29
11. rearm the callback if it is non zero For a complete description of ibnotify refer to the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual 3 Note The ibnotify callback is executed in a separate thread of execution from the rest of your application If your application will be performing other NI 488 2 operations while it is using ibnotify use the per thread NI 488 2 globals that are provided by the ThreadIbsta ThreadIberr ThreadIbcnt and ThreadIbcnt1 functions described in the Writing Multithreaded Win32 NI 488 2 Applications section of this chapter In addition if your application needs to share global variables with the callback use a synchronization primitive for example a semaphore to protect access to any globals For more information about the use of synchronization primitives refer to the documentation about using Win32 synchronization objects that came with your development tools ibnotify Programming Example The following code is an example of how you can use ibnotify in your application Assume that your GPIB device is a multimeter that you program it to acquire a reading by sending SEND DATA The multimeter requests service when it has a reading ready and each reading is a floating point value In this example globals are shared by the Callback thread and the main thread and the access of the globals is not protected by synch
12. 2 12 GPIB ENET network settings viewing or changing 2 15 to 2 16 assigning IP address 2 15 configuring advanced IP settings 2 15 updating GPIB ENET firmware 2 16 GPIB ENET 100 network settings viewing or changing 2 16 to 2 17 configuring network parameters 2 16 updating GPIB ENET 100 firmware 2 17 GPIB instruments See also communicating with instruments Instruments Enumeration Failed message 2 6 Instruments not Found message 2 6 scanning for 2 5 to 2 6 viewing information about 2 11 to 2 12 GPIB interface adding new 2 4 to 2 5 deleting 2 5 viewing or changing settings 2 9 to 2 11 Windows Me 98 95 2 9 to 2 10 Windows 2000 NT 2 10 to 2 11 National Instruments Corporation l 5 Index H handshake lines A 3 help See online help Help display Interactive Control utility online help function table 6 9 Help option function Interactive Control utility 6 9 high speed data transfers HS488 7 2 to 7 3 cable length 7 2 7 3 enabling HS488 7 2 to 7 3 system configuration effects 7 3 HS488 See high speed data transfers HS488 HSS488 configuration message 7 3 ibask function 7 3 ibclr function clearing devices 3 9 using in Interactive Control utility example 6 3 ibent and ibentl variables 3 7 ibconfig function changing cable length 7 3 determining assertion of EOI line 7 2 enabling autopolling 7 13 enabling high speed data transfers 7 2 to 7 3 ibdev function opening devices 3 8 u
13. 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application Device Communication Step 4 Communicate with the Devices Communicate with the devices by sending them the IDN query and then reading back the responses Many devices respond to this query by returning a description of the device Refer to the documentation that came with your GPIB devices to see specific instruction on the proper way to communicate with them Step 4a Use SendList to send the IDN query command to multiple GPIB devices The address is the list of GPIB devices to be queried The buffer that you pass to SendList is the command message to the device Step 4b Use Receive for each device to read the responses from each device Continue communicating with the GPIB devices until you are finished Cleanup Step 5 Place the Interface Offline before Exiting Your Application Use ibon1 to put the interface offline before you exit the application Language Specific Programming Instructions The following sections describe how to develop compile and link your Win32 NI 488 2 applications using various programming languages Microsoft Visual C C Version 2 0 or Later Before you compile your Win32 C application make sure that the following lines are included at the beginning of your program include lt windows h gt include decl 32 h To compile and link a Win32 console application named cprog in a DOS shell type the foll
14. 46 4C 55 4B 45 2C 20 34 FLUKE 4 35 2C 20 34 37 39 30 31 5 47901 37 33 2C 20 31 2E 36 20 73 1 6 44 31 2E 30 OA D 10 When you finish communicating with the device make sure you put it offline using the ibon1 command as follows ud0 ibonl 0 0100 cmp1 6 3 NI 488 2 User Manual for Windows Chapter 6 Interactive Control Utility The ibonl command properly closes the device handle and the udo prompt is no longer available 9 To exit Interactive Control type q Interactive Control Syntax Number Syntax String Syntax The following special rules apply to making calls from the Interactive Control utility e The ud or BoardId parameter is implied by the Interactive Control prompt therefore it is never included in the call e The count parameter to functions is unnecessary because buffer lengths are automatically determined by Interactive Control e Function return values are handled automatically by Interactive Control In addition to printing out the return ibsta value for the function it also prints other return values e Ifyou do not know what parameters are appropriate to pass to a given function call type in the function name and press lt Enter gt The Interactive Control utility then prompts you for each required parameter You can enter numbers in either hexadecimal or decimal format Hexadecimal numbers You must prefix hexadecimal numbers with ox For example ibpad 0x16 sets the primary a
15. 488 2 calls and multi device NI 488 2 calls brd or all dev brd Table 3 1 shows the condition that each bit position represents the bit mnemonics and the type of calls for which the bit can be set For a detailed explanation of each status condition refer to Appendix B Status Word Conditions Table 3 1 Status Word Layout Bit Hex Mnemonic Pos Value Type Description ERR 15 8000 dev brd NI 488 2 error TIMO 14 4000 dev brd Time limit exceeded END 13 2000 dev brd END or EOS detected SRQI 12 1000 brd SRQ interrupt received RQS 11 800 dev Device requesting service CMPL 8 100 dev brd T O completed LOK 7 80 brd Lockout State REM 6 40 brd Remote State CIC 5 20 brd Controller In Charge ATN 4 10 brd Attention is asserted TACS 3 8 brd Talker LACS 2 4 brd Listener DTAS 1 2 brd Device Trigger State DCAS 0 1 brd Device Clear State NI 488 2 User Manual for Windows 3 6 ni com Chapter 3 Developing Your NI 488 2 Application The language header file defines each of the ibsta status bits You can test for an ibsta status bit being set using the bitwise and operator amp in C C For example the ibsta ERR bit is bit 15 of ibsta To check for an NI 488 2 error use the following statement after each NI 488 2 call if ibsta amp ERR printf NI 488 2 error encountered Error Variable iberr If the ERR bit is set in ibsta an NI 488 2 error has o
16. 9 simple instrument control 3 1 to 3 2 application programming models multiple interfaces or multiple GPIB devices 3 10 to 3 12 becoming Controller In Charge 3 10 communicating with devices 3 11 to 3 12 determining GPIB address of device 3 11 general steps and examples 3 10 to 3 12 initialization 3 10 initializing devices 3 11 items to include 3 10 placing device offline 3 12 single GPIB device 3 8 to 3 9 clearing device 3 9 communicating with device 3 9 general steps and examples 3 8 to 3 9 initialization 3 8 to 3 9 items to include 3 8 NI 488 2 User Manual for Windows Index placing device offline before exiting 3 9 applications existing See existing applications running asynchronous event notification in Win32 applications 7 4 to 7 9 calling ibnotify function 7 4 to 7 5 ibnotify programming example 7 5 to 7 9 ATN attention line table A 3 ATN status word condition bit position hex value and type table 3 6 description B 4 automatic serial polling See serial polling auxiliary functions Interactive Control utility 6 9 to 6 10 board calls See NI 488 2 calls Borland C C programming instructions 3 12 buffer option function Interactive Control utility 6 10 bus management and device level calls 7 11 C C language Borland C C programming instructions 3 12 direct entry for application development 3 13 to 3 16 directly accessing gpib 32 dll exports 3 15 to 3 16 gp
17. 98 95 complete the following steps 1 Select Start Settings Control Panel 2 Double click on the System icon 3 Select the Device Manager tab and click on the View devices by type button 4 Click on the National Instruments GPIB Interfaces icon 5 Click on the Properties button 6 Select the Device Templates tab and rename the template as described in your application documentation 7 Click on the OK button twice to save your changes and exit Windows 2000 NT To reconfigure GPIB device templates in Windows 2000 NT complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on any GPIB interface and select Properties from the drop down menu that appears 4 Select the device template that you want to modify such as DEV1 5 Click on the Configure button and rename the device template as described in your application documentation 6 Click on the OK button twice to save your changes and exit NI 488 2 User Manual for Windows 2 12 ni com Chapter 2 Measurement amp Automation Explorer Enable Disable NI 488 2 DOS Support To enable or disable DOS support for your NI 488 2 application refer to one of the following sections Windows Me 98 95 To enable or disable NI 488 2 DOS support in Windows Me 98 95 complet
18. Application Before exiting your application you need to free gpib 32 d11 with the following command FreeLibrary Gpib32Lib For more examples of directly accessing gpib 32 d11 refer to the direct entry sample programs dlldevquery c and d114882query c installed with the NI 488 2 software For more information about direct entry refer to the online help for your development environment Running Existing NI 488 2 Applications Running Existing Win32 and Win16 NI 488 2 Applications The NI 488 2 software includes the necessary components to allow existing Win32 and Win16 NI 488 2 applications to run properly Running Existing DOS NI 488 2 Applications Under Windows Me 98 95 To configure the NI 488 2 software to run existing DOS NI 488 2 applications complete the following steps 1 Make sure that no older version of the NI 488 2 DOS device driver is being loaded from your config sys file To do so complete the following steps a Locate your config sys file and open it for editing b Find the following line device lt path gt gpib com where lt paths refers to the drive and directory where gpib com is located c If that line appears type REM at the beginning of the line as follows REM device lt path gt gpib com d Save your config sys file and close it 2 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 3 Expand the Devices and In
19. 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 reasonable 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
20. Chapter 4 Debugging Your Application Timing Errors If your application fails but the same calls issued interactively in the Interactive Control utility are successful your program might be issuing the NI 488 2 calls too quickly for your device to process and respond to them This problem can also result in corrupted or incomplete data This should only be a problem with older non standard GPIB devices To check if your interactively issued NI 488 2 calls succeed use the Interactive Control utility To start the Interactive Control utility complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB interface and select Interactive Control from the drop down menu that appears 4 At the command prompt type NI 488 2 API calls to communicate interactively with the your instrument For example you might use ibdev ibclr ibwrt ibrd and ibonl To view the online help for Interactive Control type he1p at the Interactive Control command prompt A well behaved IEEE 488 device does not experience timing errors If your device is not well behaved you can test for and resolve the timing error by single stepping through your program and inserting finite delays between each NI 488 2 call One way to do this is to have your device c
21. DLL E EABO error code C 5 EADR error code C 4 EARG error code C 4 EBUS error code C 8 ECAP error code C 7 ECIC error code C 2 to C 3 EDMA error code C 6 EDVR error code description C 2 troubleshooting D 1 to D 2 EFSO error code C 7 end of string character See EOS END status word condition bit position hex value and type table 3 6 description B 2 ENEB error code C 5 to C 6 ENOL error code C 3 NI 488 2 User Manual for Windows Index EOI end or identify line purpose table A 3 termination of data transfers 7 1 EOIP error code C 6 to C 7 EOS configuring EOS mode 7 1 to 7 2 EOS comparison method 7 1 EOS read method 7 2 EOS write method 7 1 ERR status word condition bit position hex value and type table 3 6 description B 2 error codes and solutions EABO C 5 EADR C 4 EARG C 4 EBUS C 8 ECAP C 7 ECIC C 2 to C 3 EDMA C 6 EDVR C 2 D 1 to D 2 EFSO C 7 ENEB C 5 to C 6 ENOL C 3 EOIP C 6 to C 7 ESAC C 5 ESRQ C 8 to C 9 ESTB C 8 ETAB C 9 GPIB error codes table C 1 error conditions communication errors 4 5 repeat addressing 4 5 termination method 4 5 configuration errors 4 3 Interactive Control utility error information 6 10 to 6 11 timing errors 4 4 error variable iberr 3 7 ESAC error code C 5 NI 488 2 User Manual for Windows l 4 ESRQ error code C 8 to C 9 ESTB error code C 8 ETAB error code C 9 event notification See asynchronous even
22. NI 488 2 Getting Started Wizard How do I troubleshoot problems Run the NI 488 2 Troubleshooting Wizard To do so select Start Programs National Instruments NI 488 2 Explore GPIB Then select Help Troubleshooting NI 488 2 Troubleshooting Wizard How can I determine which version of the NI 488 2 software I have installed To view the NI 488 2 software version complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Software directory by clicking on the next to the folder 3 Click on NI 488 2 Software Measurement amp Automation Explorer displays the version number of the NI 488 2 software in the right window pane National Instruments Corporation E 1 NI 488 2 User Manual for Windows Appendix E Windows 2000 NT Common Questions How can I determine which type of GPIB hardware I have installed Select Start Programs National Instruments NI 488 2 Explore GPIB and expand the Devices and Interfaces directory by clicking on the next to the folder Measurement amp Automation Explorer lists your installed GPIB hardware under Devices and Interfaces How many GPIB interfaces can I configure for use with the NI 488 2 software You can configure the NI 488 2 software to communicate with up to four GPIB interfaces How many devices can I configure for use with the NI 488 2 software You can config
23. NI 488 2 User Manual for Windows Glossary CFE CFGn CIC CPU D DAV DCL device level function DIO1 through DIO8 DLL DMA driver E END or END Message EOI Configuration Enable The GPIB command which precedes CFGn and is used to place devices into their configuration mode These GPIB commands CFG1 through CFG15 follow CFE and are used to configure all devices for the number of meters of cable in the system so HS488 transfers occur without errors Controller In Charge The device that manages the GPIB by sending interface messages to other devices Central processing unit Data Valid One of the three GPIB handshake lines See handshake Device Clear The GPIB command used to reset the device or internal functions of all devices See SDC A function that combines several rudimentary board operations into one function so that the user does not have to be concerned with bus management or other GPIB protocol matters The GPIB lines that are used to transmit command or data bytes from one device to another Dynamic link library Direct memory access High speed data transfer between the GPIB board and memory that is not handled directly by the CPU Not available on some systems See programmed I O Device driver software installed within the operating system A message that signals the end of a data string END is sent by asserting the GPIB End or Identify EOI line with the last data byte
24. NI 488 2 software language interfaces 3 3 viewing version 2 8 NI Spy utility debugging applications 4 1 exiting 5 3 locating errors 5 2 online help 5 2 overview 5 1 performance considerations 5 3 starting 5 1 to 5 2 viewing properties for recorded calls 5 2 NRFD not ready for data line table A 3 number syntax in Interactive Control utility 6 4 0 online help accessing xi NI 488 2 online help 2 14 NI Spy online help 5 2 P parallel polling 7 17 to 7 19 implementing 7 17 to 7 19 using NI 488 2 calls 7 17 to 7 19 multi device 7 19 traditional 7 17 to 7 18 PPoll routine 7 19 PPollConfig routine 7 19 PPollUnconfig routine 7 19 primary GPIB address A 2 problem solving See debugging troubleshooting and common questions ni com programming See application development debugging NI 488 2 programming techniques Q q function Interactive Control utility 6 10 R ReadStatusByte routine 7 15 Receive function 3 12 REM status word condition bit position hex value and type table 3 6 description B 4 REN remote enable line table A 3 repeat addressing 4 5 repeat previous function function Interactive Control utility 6 9 requesting service See service requests RQS status word condition bit position hex value and type table 3 6 description B 3 running existing applications See existing applications running S secondary GPIB address A 2 SendIFC
25. Programming Techniques Waiting for GPIB Conditions You can use the ibwait function to obtain the current ibsta value or to suspend your application until a specified condition occurs on the GPIB If you use ibwait with a parameter of zero it immediately updates ibsta and returns If you want to use ibwait to wait for one or more events to occur pass a wait mask to the function The wait mask should always include the TIMO event otherwise your application is suspended indefinitely until one of the wait mask events occurs Asynchronous Event Notification in Win32 NI 488 2 Applications Win32 NI 488 2 applications can asynchronously receive event notifications using the ibnotify function This function is useful if you want your application to be notified asynchronously about the occurrence of one or more GPIB events For example you might choose to use ibnotify if your application only needs to interact with your GPIB device when it is requesting service After calling ibnotify your application does not need to check the status of your GPIB device Then when your GPIB device requests service the NI 488 2 driver automatically notifies your application that the event has occurred by invoking a callback function The callback function is registered with the NI 488 2 driver when the ibnotify call is made Calling the ibnotify Function ibnotify has the following function prototype ibnotify int ud unit descriptor int mask b
26. Windows e The NI 488 2 Function Reference Manual for Windows describes the NI 488 2 API e The GPIB Hardware Guide contains detailed instructions on how to install and configure your GPIB hardware This guide also includes hardware and software specifications and compliance information To view these documents online insert your NI 488 2 for Windows CD When the NI 488 2 Software for Windows screen appears select the View Documentation option The View Documentation Wizard helps you find the documentation that you want to view You can also view these documents at ni com manuals Accessing the NI 488 2 Online Help The NI 488 2 for Windows Online Help addresses questions you might have about NI 488 2 includes troubleshooting information and describes the NI 488 2 API You can access the NI 488 2 online help as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB 2 Select Help Help Topics NI 488 2 National Instruments Corporation xi NI 488 2 User Manual for Windows About This Manual Conventions 3 bold TEEE 488 and TEEE 488 2 italic monospace monospace bold monospace italic Nl 488 2 User Manual for Windows xii The following conventions appear in this manual The symbol leads you through nested menu items and dialog box options to a final action The sequence File Page Setup Options directs you to pull down the File menu select the Page Setup item a
27. aree e e EETA vues EE E A EEE E E OE EA e 7 12 Service Requests from IEEE 488 Devices ssesseesesrereereeesresrsresreresrrsreresre 7 12 Service Requests from IEEE 488 2 Devices ssssessesseeessesesreseresrrsrrsesresreee 7 12 Automatic Serial Polling 0 eee ceeceeeeseeseseeesesseeeaeseeeaeeasensesaeenaeeaes 7 13 Stuck SRO S tate eree ee e nae aS ea A E N ERE eect 7 13 Autopolling and Interrupts sssseseseeeseeseeesessessessresessessessrsssessese 7 14 SRQ and Serial Polling with Device Level Traditional NI 488 2 Calls 7 14 SRQ and Serial Polling with Multi Device NI 488 2 Calls ee 7 15 Example 1 Using FindRQS enrian iera eiria 7 16 Example 2 Using AlISpoll oo eee cseceeeseeeeeseeeseeseeeaeenees 7 16 Parallel Pollan evs ticcesedceacevcusvecbintestececte a soeneevers ereascuvateees tease Soeuats aed geostants eeea Seavey 7 17 Implementing a Parallel Pollo eee onneen ienesis ess 7 17 Parallel Polling with Traditional NI 488 2 Calls eee 7 17 Parallel Polling with Multi Device NI 488 2 Calls oo eee 7 19 Appendix A GPIB Basics Appendix B Status Word Conditions Appendix C Error Codes and Solutions Appendix D Windows Me 98 95 Troubleshooting and Common Questions NI 488 2 User Manual for Windows viii ni com Contents Appendix E Windows 2000 NT Common Questions Appendix F Technical Support Resources Glossary Index Figures Figure 1 1 Linear and Star System Configuration 00 eee
28. can also use the NI 488 2 software in most non Controller situations These situations are known as Talker Listener applications because the interface is not the GPIB Controller A Talker Listener application typically uses ibwait with a mask of 0 to monitor the status of the interface Then based on the status bits set in ibsta the application takes whatever action is appropriate For example National Instruments Corporation 7 11 NI 488 2 User Manual for Windows Chapter 7 NI 488 2 Programming Techniques Serial Polling the application could monitor the status bits TACS Talker Active State and LACS Listener Active State to determine when to send data to or receive data from the Controller The application could also monitor the DCAS Device Clear Active State and DTAS Device Trigger Active State bits to determine if the Controller has sent the device clear DCL or SDC or trigger GET messages to the interface If the application detects a device clear from the Controller it might reset the internal state of message buffers If it detects a trigger message from the Controller the application might begin an operation such as taking a voltage reading if the application is actually acting as a voltmeter You can use serial polling to obtain specific information from GPIB devices when they request service When the GPIB SRQ line is asserted it signals the Controller that a service request is pending The Controller must th
29. command used to address a device to be a Listener or a Talker when extended two byte addressing is used The complete address is a MLA or MTA address followed by an MSA address There are 31 secondary addresses for a total of 961 distinct listen or talk addresses for devices My Talk Address A GPIB command used to address a device to be a Talker It can be any one of the 31 primary addresses The concurrent processing of more than one program or task NI 488 2 User Manual for Windows Glossary NDAC NRFD P parallel poll PC PCI PIO PPC PPD PPE PPU programmed I O R resynchronize RQS Not Data Accepted One of the three GPIB handshake lines See handshake Not Ready For Data One of the three GPIB handshake lines See handshake The process of polling all configured devices at once and reading a composite poll response See serial poll Personal computer Peripheral Component Interconnect See programmed I O Parallel Poll Configure The GPIB command used to configure an addressed Listener to participate in polls Parallel Poll Disable The GPIB command used to disable a configured device from participating in polls There are 16 PPD commands Parallel Poll Enable The GPIB command used to enable a configured device to participate in polls and to assign a DIO response line There are 16 PPE commands Parallel Poll Unconfigure The GPIB command used to disable used to disable any device fr
30. eceeceeseescceseesseeseceeeeseeseeesesseeeaeeseeenees 2 16 View or Change GPIB ENET 100 Network Settings Windows Me 98 95 Only 2 16 Device Configuration c n ccccsciesiscssepexads eobedecs deen san stbde AANA A REE i 2 16 Update GPIB ENET 100 Firmware ee eeeeseeseeseeneceseeeeeeeeseeeeeeseeenees 2 17 Chapter 3 Developing Your NI 488 2 Application Simple Instrument Control sssini ini sua decuesebubes ie E rE E ia 3 1 Interactive Instrument Control sssessssesseeessrerestsresresesresesrrsrsrestentstesterestentesrsreerseneeees 3 2 Choosing Your Programming Methodology eee eeceseesseseceeeseeesecseeesesseetseeseeeaees 3 3 Choosing a Method to Access the NI 488 2 Driver eee eects eeeeees 3 3 NI 488 2 Language Interfaces 00 0 eee eeeeseceeeeeceeeeeeeseeseeenees 3 3 Direct Entry Access 5 a a inl pete eet ae 3 3 Choosing How to Use the NI 488 2 API oo eee ceeesceereeeeeeseceeeneeeeeeeaees 3 4 Communicating with a Single GPIB Device eee eee 3 4 Using Multiple Interfaces and or Multiple Devices 0 eee 3 5 Checking Status with Global Variables ccc ee ceeeseeeeeeseeseceeeeseeeeceseceeesesseeeaeeaees 3 5 Status Word Abstain nrasane e ar apna 3 5 Error Variable iDerr ccccccccssecsssccesesceesseeeeseecesaeceseeesseeeeseaeeesseeessaaees 3 7 Count Variables ibcnt and ibcntl ee eeccceseceeeseceeeneeeeeneeeesseeeesseeeesneeeess 3 7 Using Interactive Control to Communicate with Devices
31. ee eeeeeeseeeeeeeeneeees 1 1 Figure 1 2 Example of Multiboard System Configuration 0 0 00 eee seen 1 2 Figure 2 1 Measurement amp Automation Explorer oo ee eeeeeeeseeseceeerseneeeaes 2 2 Figure 2 2 Viewing Documentation on Your CD eee eee ceceeseeeeeeeeseeeseeneeees 2 3 Figure 2 3 NI 488 2 Troubleshooting Wizard 0 eee eeeeeseeseeeseeteeeseeseeneeeaes 2 4 Figure 2 4 NI 488 2 Communicator oo eee eee cseseeeeeeseeeseceeeeseeaeeesecaeensesaeenaes 2 7 Figure 2 5 NI 488 2 Calls Recorded by NI Spy 0 eee eeeeeesecseeeeeneeneeeeenaes 2 9 Figure 2 6 Properties Dialog Box in Windows Me 98 95 n se 2 10 Figure 2 7 GPIB Configuration Utility in Windows NT eee eeeeeeeereeeeeees 2 11 Figure 3 1 NI 488 2 Communicator oo eee cece eeeeeeeeeeeseeeeeeseeseenseseensesseenaes 3 2 Figure 4 1 NI 488 2 Calls Recorded by NI Spy 0 0 ceeeceeseeseeeeeneeeeeeeeaes 4 2 Figure 5 1 NI 488 2 Calls Recorded by NI Spy 0 eee eee eeceseeseeeeeneeeseeeeaes 5 2 Figure 6 1 Instrument Address in Measurement amp Automation Explorer 6 2 Figure A 1 GPIB Address Bits sesso nerina iiki A 2 Tables Table 3 1 Status Word Layout cscccsdsceccsuscessavcsidesstacesteuae sees seasons SRA E 3 6 Table 6 1 Syntax for Device Level Traditional NI 488 2 Calls in Anteractive Controls ci0c s 5 wagcesea sat vita Sees Oi E eae 6 5 Table 6 2 Syntax for Board Level Traditional NI 488 2 Calls in Interactive Controls secs iaire
32. either SRQ is asserted or the timeout period is exceeded The following examples use these calls to detect SRQ and then determine which device requested service In these examples three devices are present on the GPIB at addresses 3 4 and 5 and the GPIB interface is designated as bus index 0 The first example uses FindRQS to determine which device is requesting service and the second example uses Al1Spo11 to serial poll all three devices Both examples use Wait SRQ to wait for the GPIB SRQ line to be asserted National Instruments Corporation 7 15 NI 488 2 User Manual for Windows Chapter 7 NI 488 2 Programming Techniques Example 1 Using FindROS This example shows you how to use FindRQS to find the first device that is requesting service void GetASerialPollResponse char DevicePad char DeviceResponse char SerialPollResponse 0 int WaitResult Addr4882_ t Addrlist 4 3 4 5 NOADDR WaitSRQ 0 amp WaitResult if WaitResult printf SRQ is asserted n FindRQS 0 AddrList amp SerialPollResponse if ibsta amp ERR printf Device at pad x returned byte x n AddrList ibent int SerialPollResponse DevicePad AddrList ibent DeviceResponse SerialPollResponse return Example 2 Using AllSpoll This example shows you how to use A11Spo11 to serial poll three devices with a single call void GetAllSerialPollResponses Addr4882 t AddrList short Respons
33. fault National Instruments Corporation 7 7 NI 488 2 User Manual for Windows Chapter 7 NI 488 2 Programming Techniques condition to report if SpollByte expectedResponse printf Device returned invalid response Status byte 0x x n SpollByte DeviceError TRUE return 0 Read the data from the device If the ERR bit is set in ibsta then print an error message and return LocalIbsta ibrd LocalUd ReadBuffer 40L if Locallbsta amp ERR printf ibrd failed No more callbacks n DeviceError TRUE return 0 The string returned by ibrd is a binary string whose length is specified by the byte count in ibcntl However many GPIB instruments return ASCII data strings and this example makes this assumption Because of this it is possible to add a NULL character to the end of the data received and use the printf function to display the ASCII data The following code illustrates that ReadBuffer ibcntl 0 Convert the data into a numeric value sscanf ReadBuffer Sf amp Readings ReadingsTaken Display the data printf Reading f n Readings ReadingsTaken ReadingsTaken 1 if ReadingsTaken gt 1000 return 0 else Issue a request to the device to send the data and rearm callback on RQS LocalIbsta ibwrt LocalUd SEND DATA 9L if LocalIbsta amp ERR printf ibwrt failed No more callbacks n
34. gt doswinl6 gpib nt com where lt paths is the directory in which you installed the NI 488 2 software 3 Remove REM from the last line so that it reads as follows device lt path gt doswinl6 gpib nt com To disable DOS support add REM back to the line where it was removed Access Additional Help and Resources To access additional help and resources for the NI 488 2 software and your GPIB hardware refer to the following sections NI 488 2 Online Help The NI 488 2 for Windows Online Help addresses questions you might have about NI 488 2 includes troubleshooting information and describes the NI 488 2 API You can access the NI 488 2 online help as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB 2 Select Help Help Topics NI 488 2 National Instruments GPIB Web Site To access the National Instruments Web site for GPIB select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer Then select Help National Instruments on the Web GPIB Home Page NI 488 2 User Manual for Windows 2 14 ni com Chapter 2 Measurement amp Automation Explorer View or Change GPIB ENET Network Settings Windows Me 98 95 Only To view or change the network settings of your GPIB ENET refer to the following sections For more information about your GPIB ENET network settings refer to the Getting Started with Your GPIB ENET and NI 488 2 for Window
35. guide you through configuration and basic tasks Measurement amp Automation Explorer MAX provides access to all your National Instruments DAQ GPIB IMAG IVI Motion VISA and Vx devices With Measurement amp To learn about any task Automation Explorer you can on the list click on it Configure your National Instruments hardware and software Add new channels interfaces and Some task lists include virtual instruments interactive buttons For Execute system diagnostics example to save a channel configuration to a Vio dosticac and inctrumante Figure 2 1 Measurement amp Automation Explorer Getting Started with NI 488 2 To get started with GPIB instrument communication using Measurement amp Automation Explorer complete the following steps 1 Refer to your Getting Started card and install the NI 488 2 software and your GPIB hardware If you do not have a Getting Started card complete the following steps to view your getting started documentation a Insert the NI 488 2 for Windows CD NI 488 2 User Manual for Windows 2 2 ni com Chapter 2 Measurement amp Automation Explorer b When the NI 488 2 Software for Windows screen appears select the View Documentation option as shown in Figure 2 2 DI NI 488 2 Software for Windows ano VAT 7 gt Install NI 488 2 Software On for Windows View Documentation Visit National Instruments BIL 1 Ty gt i z
36. implement parallel polling using traditional NI 488 2 calls Each step contains example code 1 Configure the device for parallel polling using the ibppc function unless the device can configure itself for parallel polling ibppc requires an 8 bit value to designate the data line number the ist sense and whether the function configures the device for the parallel poll The bit pattern is as follows 011 ES D2 Di DO E is 1 to disable parallel polling and 0 to enable parallel polling for that particular device S is 1 if the device is to assert the assigned data line when ist is 1 and 0 if the device is to assert the assigned data line when ist is 0 D2 through DO determine the number of the assigned data line The physical line number is the binary line number plus one For example DIO3 has a binary bit pattern of 010 National Instruments Corporation 7 17 NI 488 2 User Manual for Windows Chapter 7 NI 488 2 Programming Techniques The following example code configures a device for parallel polling using traditional NI 488 2 calls The device asserts DIO7 if its ist is 0 In this example the ibdev command opens a device that has a primary address of 3 has no secondary address has a timeout of 3 s asserts EOI with the last byte of a write operation and has EOS characters disabled The following call configures the device to respond to the poll on DIO7 and to assert the line in the case when its ist is 0 Pass the binary
37. mark button on the NI Spy toolbar and then clicking on the area of the screen about which you have a question Locating Errors with NI Spy All NI 488 2 calls returned with an error are displayed in red within the main NI Spy window Viewing Properties for Recorded Calls To see the detailed properties of any call recorded in the main NI Spy window double click on the call The Call Properties window appears It contains general input output and buffer information NI 488 2 User Manual for Windows 5 2 ni com Chapter 5 NI Spy Utility Exiting NI Spy When you exit NI Spy its current configuration is saved and used to configure NI Spy when you start it again Unless you save the data captured in NI Spy before you exit that information is lost To save the captured data click on the red circled X button on the toolbar and select File Save As to save the dataina spy file After you save your data select File Exit to exit the NI Spy utility Performance Considerations NI Spy can slow down the performance of your NI 488 2 application and certain configurations of NI Spy have a larger impact on performance than others For example configuring NI Spy to record calls to an output file or to use full buffers might have a significant impact on the performance of both your application and your system For this reason use NI Spy only while you are debugging your application or in situations where performance is not criti
38. routine 3 10 SendList function 3 12 serial polling 7 12 to 7 17 application example using NI 488 2 routines 7 16 to 7 17 automatic serial polling 7 13 to 7 14 autopolling and interrupts 7 14 stuck SRQ state 7 13 service requests from IEEE 488 devices 7 12 National Instruments Corporation I 9 Index from IEEE 488 2 devices 7 12 SRQ and serial polling device level traditional NI 488 2 calls 7 14 to 7 15 multi device NI 488 2 calls 7 15 to 7 17 service requests serial polling IEEE 488 devices 7 12 IEEE 488 2 devices 7 12 stuck SRQ state 7 13 set 488 2 v function Interactive Control utility 6 9 set udname function Interactive Control utility 6 9 setting up your system See configuration SRQ service request line purpose table A 3 serial polling automatic serial polling 7 13 to 7 14 using device level traditional NI 488 2 calls 7 14 to 7 15 using multi device NI 488 2 calls 7 15 to 7 17 stuck SRQ state 7 13 SRQI status word condition bit position hex value and type table 3 6 description B 3 status word ibsta 3 5 to 3 7 ATN B 4 CIC B 4 CMPL B 3 DCAS 7 12 B 5 DTAS 7 12 B 5 END B 2 ERR B 2 Interactive Control utility example 6 10 LACS 7 12 B 5 LOK B 3 programming considerations 3 5 to 3 7 NI 488 2 User Manual for Windows Index REM B 4 RQS B 3 SRQI B 3 status word layout table 3 6 B 1 TACS 7 12 B 4 TIMO B 2 string syntax in Interactive Control utili
39. soniai sasksiasdeasstesadescassesisesbaces 6 7 Table 6 3 Syntax for Multi Device NI 488 2 Calls in Interactive Control 6 8 National Instruments Corporation ix NI 488 2 User Manual for Windows Contents Table 6 4 Auxiliary Functions in Interactive Control eeeeeeseeeeeereeneee 6 9 Table A 1 GPIB Handshake Lines 20 0 eee iiini ia A 3 Table A 2 GPIB Interface Management Lines 000 eee ee eeeeeseceeeneeeseereeeneees A 3 Table B 1 Status Word Layout ci icccsscessecscsscsdecueesicaiscssceachsssesesesdaseatsonsstscssesestiness B 1 Table C 1 GPIB Error Codes cis 2cssctevsees ss seiseges cea iaaugcasssskguaestasdetteces ea steosdiassieteeade C 1 Table D 1 Device Manager Status Codes 0 ce eeeeceeseesceseseeeseeeeceseeseeeaeeseeeaeens D 3 NI 488 2 User Manual for Windows X ni com About This Manual This manual describes the features and functions of the NI 488 2 software for Windows You can use the NI 488 2 software for Windows with Windows 95 Windows 98 Windows Me Windows NT version 4 0 or Windows 2000 This manual assumes that you are already familiar with Windows Using the NI 488 2 Documentation The following NI 488 2 documentation is available on your NI 488 2 for Windows CD e The Getting Started card briefly describes how to install the NI 488 2 software and your GPIB hardware e This manual NI 488 2 User Manual for Windows describes the features and functions of the NI 488 2 software for
40. status word only after a device level call and indicates that the device is requesting service RQS is set whenever one or more positive serial poll response bytes have been received from the device A positive serial poll response byte always has bit 6 asserted Automatic serial polling must be enabled it is enabled by default for RQS to automatically appear in ibsta You can also wait for a device to request service regardless of the state of automatic serial polling by calling ibwait witha mask that contains RQS Do not issue an ibwait call on RQS for a device that does not respond to serial polls Use ibrsp to acquire the serial poll response byte that was received RQS is cleared when all of the stored serial poll response bytes have been reported to you through the ibrsp function CMPL dev brd LOK brd CMPL indicates the condition of I O operations It is set whenever an I O operation is complete CMPL is cleared while the I O operation is in progress LOK indicates whether the interface is in a lockout state While LOK is set the EnableLocal or ibloc call is inoperative for that interface LOK is set whenever the GPIB interface detects that the Local Lockout LLO message has been sent either by the GPIB interface or by another Controller LOK is cleared when the System Controller unasserts the Remote Enable REN GPIB line National Instruments Corporation B 3 NI 488 2 User Manual for Windows Appendix B Status Word C
41. the GPIB interface with a GPIB cable Then scan for instruments again as described in the previous section Scan for GPIB Instruments Instruments Enumeration Failed Ifthe Instruments Enumeration Failed message appears in the right window pane Measurement amp Automation Explorer found too many Listeners on the GPIB To solve this problem refer to the following possible solutions e Ifyou have a running GPIB Analyzer with the GPIB handshake option enabled disable the GPIB handshake option in the GPIB Analyzer e If you have a GPIB extender in your system Measurement amp Automation Explorer cannot detect any instruments connected to your GPIB interface Instead you can verify communication with your instruments using the Interactive Control utility To do so select Tools NI 488 2 Interactive Control For more information about verifying instrument communication type help Interactive Control getting started at the Interactive Control command prompt Communicate with Your Instrument To establish basic or advanced communication with your instruments refer to the following sections For more information about instrument communication and a list of the commands that your instrument understands refer to the documentation that came with your GPIB instrument Most instruments respond to the IDN command by returning an identification string NI 488 2 User Manual for Windows 2 6 ni com Chapter 2 Measurement amp Autom
42. through the Technical Support section of ni com NI Developer Zone The NI Developer Zone at ni com zone is the essential resource for building measurement and automation systems At the NI Developer Zone you can easily access the latest example programs system configurators tutorials technical news as well as a community of developers ready to share their own techniques Customer Education National Instruments provides a number of alternatives to satisfy your training needs from self paced tutorials videos and interactive CDs to instructor led hands on courses at locations around the world Visit the Customer Education section of ni com for online course schedules syllabi training centers and class registration System Integration If you have time constraints limited in house technical resources or other dilemmas you may prefer to employ consulting or system integration services You can rely on the expertise available through our worldwide network of Alliance Program members To find out more about our Alliance system integration solutions visit the System Integration section of ni com National Instruments Corporation F 1 NI 488 2 User Manual for Windows Appendix F Technical Support Resources Worldwide Support National Instruments has offices located around the world to help address your support needs You can access our branch office Web sites from the Worldwide Offices section of ni com Branc
43. timed out was more than the other device was expecting Possible solutions for this error are as follows e Use the correct byte count in input functions or have the Talker use the END message to signify the end of the transfer e Lengthen the timeout period for the I O operation using ibtmo e Make sure that you have configured your device to send data before you request data ENEB occurs when no GPIB interface exists at the I O address specified in the configuration program This problem happens when the interface is not physically plugged into the system the I O address specified during configuration does not match the actual interface setting or there is a system conflict with the base I O address National Instruments Corporation C 5 NI 488 2 User Manual for Windows Appendix C Error Codes and Solutions Solutions EDMA 8 Make sure there is a GPIB interface in your computer that is properly configured both in hardware and software using a valid base I O address by running the NI 488 2 Troubleshooting Wizard as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB 2 Select Help Troubleshooting NI 488 2 Troubleshooting Wizard The Troubleshooting Wizard tests your GPIB interface and displays the results Solutions EOIP 10 EDMA occurs if a system DMA error is encountered when the NI 488 2 software attempts to transfer data over the GPIB using DMA Possible solutions f
44. use depend on the specific instrument The documentation for each instrument should include the GPIB commands that you need to communicate with your instrument In most cases device level traditional NI 488 2 calls are sufficient for communicating with instruments For more information refer to Chapter 3 Developing Your NI 488 2 Application How do I check for errors in my NI 488 2 application Examine the value of ibsta after each NI 488 2 call If a call fails the ERR bit of ibsta is set and an error code is stored in iberr For more information about global status variables refer to Chapter 4 Debugging Your Application What information should I have before I call National Instruments Before you call National Instruments record the results of the NI 488 2 Troubleshooting Wizard To start the NI 488 2 Troubleshooting Wizard select Start Programs National Instruments NI 488 2 Explore GPIB Then select Help Troubleshooting NI 488 2 Troubleshooting Wizard National Instruments Corporation E 3 NI 488 2 User Manual for Windows Technical Support Resources Web Support National Instruments Web support is your first stop for help in solving installation configuration and application problems and questions Online problem solving and diagnostic resources include frequently asked questions knowledge bases product specific troubleshooting wizards manuals drivers software updates and more Web support is available
45. you know which NI 488 2 call fails refer to Appendix B Status Word Conditions and Appendix C Error Codes and Solutions for help understanding why the NI 488 2 call failed This information is also available in the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual NI 488 2 Error Codes The error variable is meaningful only when the ERR bit in the status variable ibsta is set For a detailed description of each error and possible solutions refer to Appendix C Error Codes and Solutions Configuration Errors Several applications require customized configuration of the NI 488 2 driver For example you might want to terminate reads on a special end of string character or you might require secondary addressing In these cases you can either reconfigure from your application using the ibconfig function or reconfigure using the NI 488 2 Configuration utility Ss Note National Instruments recommends using ibconfig to modify the configuration If your application uses ibconfig it works properly regardless of the previous configuration For more information about using ibconfig refer to the description of ibconfig in the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual National Instruments Corporation 4 3 NI 488 2 User Manual for Windows
46. 1 count information in Interactive Control utility 6 11 count variables ibcnt and ibcntl 3 7 customer education F 1 D data lines A 2 data transfers high speed HS488 7 2 to 7 3 enabling 7 2 to 7 3 system configuration effects 7 3 terminating 7 1 to 7 2 DAV data valid line table A 3 DCAS status word condition bit position hex value and type table 3 6 description B 5 Talker Listener applications 7 12 debugging See also NI Spy utility troubleshooting and common questions communication errors 4 5 repeat addressing 4 5 termination method 4 5 configuration errors 4 2 global status variables 4 2 GPIB error codes table C 1 other errors 4 5 timing errors 4 4 DevClearList function D 11 device calls See NI 488 2 calls device level calls and bus management 7 11 Device Manager device status codes troubleshooting D 3 direct access to NI 488 2 dynamic link library 3 3 National Instruments Corporation l 3 Index documentation accessing NI 488 2 Online Help xi conventions used in manual xii related documentation xiii using NI 488 2 documentation xi DOS NI 488 2 applications enabling disabling support Windows Me 98 95 2 13 to 2 14 Windows 2000 NT 2 14 running under Windows Me 98 95 3 17 under Windows 2000 NT 3 18 DTAS status word condition bit position hex value and type table 3 6 description B 5 Talker Listener applications 7 12 dynamic link library GPIB See NI 488 2
47. 88 2 calls use NI Spy as follows 1 NI 488 2 User Manual for Windows Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer Expand the Devices and Interfaces directory by clicking on the next to the folder Right click on your GPIB interface and select NI Spy from the drop down menu that appears On the NI Spy toolbar click on the blue arrow button to start a capture Start the NI 488 2 application that you want to monitor 2 8 ni com Chapter 2 Measurement amp Automation Explorer NI Spy records and displays all NI 488 2 calls as shown in Figure 2 5 NI Spy capture on Efel x Fie Edt View Spy Help ia bel al S x k Number GPIB Calls ibsta iberr ibentl Time 1 ibdev 0 3 0 0x0 T10s 13 1 Ox0000 0x0100 0 0x0000 12 53 05 496 2 ibelr UDO 0x0100 0 0x0000 12 53 07 378 3 ibwrt UDO idn 5 0x5 0x0100 0 0x0005 12 53 15 410 4 ibrd UDO National Inst 51 0x33 0x2100 0 0x0033 12 53 18 925 5 ibwrt UDO conf dc max 11 0xB 0x0100 0 Ox000b le 40 416 6 ibwrt UDO meas de 8 0x8 0x0100 0 0x0008 12 53 52 924 7 ibrd UDO 0 9453E2 9 0x9 0x2100 0 0x0009 12 53 56 158 zi For Help press F1 Captured 7 Displayed 7 YW Figure 2 5 NI 488 2 Calls Recorded by NI Spy For more information about using NI Spy select Help Help Topics in NI Spy or refer to Chapter 5 NI Spy Utility View or C
48. Digital Interface for Programmable Instrumentation e ANSI TEEFE Standard 488 2 1992 IEEE Standard Codes Formats Protocols and Common Commands National Instruments Corporation xiii NI 488 2 User Manual for Windows Introduction This chapter describes how to set up your GPIB system Setting up and Configuring Your System Devices are usually connected with a cable assembly consisting of a shielded 24 conductor cable with both a plug and receptacle connector at each end With this design you can link devices in a linear configuration a star configuration or a combination of the two configurations Figure 1 1 shows the linear and star configurations Device A Device A Device D Device B Device C Device B Device C a Linear Configuration b Star Configuration Figure 1 1 Linear and Star System Configuration National Instruments Corporation 1 1 NI 488 2 User Manual for Windows Chapter 1 Introduction Controlling More Than One Interface Figure 1 2 shows an example of a multiboard system configuration gpibo is the access interface for the voltmeter and gpib1 is the access interface for the plotter and printer The control functions of the devices automatically access their respective interfaces One GPIB Digital Volto
49. E 488 2 defined data byte sent by a device when it is serially polled See ibsta Refers to the relationship between the GPIB driver functions and a process when executing driver functions is predictable the process is blocked until the driver completes the function The single designated Controller that can assert control become CIC of the GPIB by sending the Interface Clear IFC message Other devices can become CIC only by having control passed to them NI 488 2 User Manual for Windows Glossary T TAD Talker TCT timeout TLC ud UNL UNT Talk Address See MTA A GPIB device that sends data messages to Listeners Take Control The GPIB command used to pass control of the bus from the current Controller to an addressed Talker A feature of the GPIB driver that prevents I O functions from hanging indefinitely when there is a problem on the GPIB An integrated circuit that implements most of the GPIB Talker Listener and Controller functions in hardware Unit descriptor A variable name and first argument of each function call that contains the unit descriptor of the GPIB interface or other GPIB device that is the object of the function Unlisten The GPIB command used to unaddress any active Listeners Untalk The GPIB command used to unaddress an active Talker NI 488 2 User Manual for Windows G 8 ni com Index Numbers Symbols repeat previous function function Interactive Control uti
50. H 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 Contents About This Manual Using the NI 488 2 Documentation eee eecececseeeeeeseeesecseeeaeeseeseeeaeensesateneeeaeenaes Xi Accessing the NI 488 2 Online Help eee eeeeeeseceeensceseseensesseeeseenees xi Conventions sen anien asea EAE E EEE E ARR ANEA O Eih xii Related Documentation c secsccsscedislast sidaagsessicagesdesedhasseeadessaapestastgutsevsadedsasavsrsusnavtagesens xiii Chapter 1 Introduction Setting up and Configuring Your System eseessseessseerssrsrrsrerrererrsresrrresresesresrsrrsresese 1 1 Controlling More Than One
51. Interface esseseseeseeesseeeeersreersrrsrrsrsrrsrsresresrseee 1 2 Configuration Requirements e esesessesestseseeeeseersresteststeetsresrrsrstrsrsresreersees 1 2 Chapter 2 Measurement amp Automation Explorer OD DAA E EA ENEE E E E A AEA EAEE 2 1 Starting Measurement amp Automation Explorer eee seeeeseeseceseeeeeseessenseeeenees 2 2 Getting Started with NI 488 2 norisi ninini a E EAE E 2 2 Troubleshoot NI 488 2 Problems cccccccssssccecesssscceceessssececeeessseeeceecsssseeceeessseeeeees 2 4 Adda New GPIB Interface ove cics ccccctetentecid cadancteaccessotecaadesoasaeceevess tecancecsvsneesadeesdeisseaesoes 2 4 Deletea GPIB Int rbacesicoice e r e a se vad oes a ses eaea ia 2 5 Scan for GPIB Instruments nannsunanta 2 5 Instruments Not Found 0 cccccccccssscccceesssscceceesssseeeceesssseeeceesessseeeeeesseeeceeens 2 6 Instruments Enumeration Failed ccccccscccccecesssececeesessceceeesssseeeeeeenseeeeees 2 6 Communicate with Your Instrument ccccccccccsssscccceeessseeeceeesnsseececessseesceeeessseeeeees 2 6 Basic Communication Query Write Read 00 eeeeeececenseeseeceeeeeaeeeeneeneeeeaee 2 7 Advanced Communication ccccccssccccccssssscececesssscececeesseeeceeesssseeeeeeeessseeeees 2 8 View NI 488 2 Software Version c cccccccsssccccessssssccceesessseeccecssseeeccesesseeeeeeessseeeeeeesses 2 8 Monitor Record and Display NI 488 2 Calls cee ecesseceeeseceeeesec
52. NI 488 2 NI 488 2 User Manual for Windows Qr NATIONAL gt INSTRUMENTS August 2000 Edition Worldwide Technical Support and Product Information 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 New Zealand 09 914 0488 Norway 32 27 73 00 Poland 0 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 2528 7227 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 1998 2000 National Instruments Corporation All rights reserved Important Information Warranty The media on which you receive National Instruments software are warranted not to fail to execute programming instructions due to defects in material
53. National Instruments Corporation D 7 NI 488 2 User Manual for Windows Appendix D Windows Me 98 95 Troubleshooting and Common Questions How can I start communicating with my GPIB instrument For simple instrument communication use the NI 488 2 Communicator For instructions on how to use the NI 488 2 Communicator refer to the Basic Communication Query Write Read section in Chapter 2 Measurement amp Automation Explorer How do I check for errors in my NI 488 2 application Examine the value of ibsta after each NI 488 2 call If a call fails the ERR bit of ibsta is set and an error code is stored in iberr For more information about global status variables refer to Chapter 4 Debugging Your Application What information should I have before I call National Instruments Before you call National Instruments record the results of the NI 488 2 Troubleshooting Wizard To start the NI 488 2 Troubleshooting Wizard select Start Programs National Instruments NI 488 2 Explore GPIB Then select Help Troubleshooting NI 488 2 Troubleshooting Wizard NI 488 2 User Manual for Windows D 8 ni com Windows 2000 NT Common Questions This appendix answers some common questions about the NI 488 2 software for Windows 2000 NT Common Questions How do I get started To get started with your GPIB hardware and the NI 488 2 software use the NI 488 2 Getting Started Wizard To do so select Start Programs National Instruments
54. PI input and output values from all Win32 Win16 and DOS NI 488 2 applications To start NI Spy complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB interface and select NI Spy from the drop down menu that appears 4 On the NI Spy toolbar click on the blue arrow button to start a capture Start the NI 488 2 application that you want to monitor National Instruments Corporation 4 1 NI 488 2 User Manual for Windows Chapter 4 Debugging Your Application NI Spy records and displays all NI 488 2 calls as shown in Figure 4 1 HI Spy capture on o x File Edit View Spy Help ta bel d l gt o E x x Number GPIB Calls ibsta iberr ibentl Time 1 ibdev 0 3 0 0x0 T10s 13 1 0x0000 0x0100 0 0x0000 12 53 05 496 2 ibelr UDO 0x0100 0 0x0000 12 53 07 378 3 ibwrt UDO idn 5 0x5 0x0100 0 0x0005 12 53 15 410 4 ibra UDO National Inst 51 0x33 0x2100 0 0x0033 12 53 18 925 5 ibvert UDO conf de max 11 0xB 0x0100 0 0x000b 12 53 40 416 6 ibwert UDO meas de 8 0x8 0x0100 0 0x0008 12 53 52 924 7 ibrd UDO 0 9453E2 9 0x9 0x2100 0 0x0009 12 53 56 158 gt For Help press F1 Captured 7 Displayed 7 Ui Figure 4 1 NI 488 2 Calls Recorded by NI Spy Fo
55. T firmware 2 16 viewing or changing GPIB ENET 100 network settings 2 16 to 2 17 configuring network parameters 2 16 updating GPIB ENET 100 firmware 2 17 viewing or changing GPIB interface settings 2 9 to 2 11 Windows Me 98 95 2 9 to 2 10 Windows 2000 NT 2 10 to 2 11 Message Available MAV bit 7 12 messages sending across GPIB A 2 to A 3 data lines A 2 handshake lines A 3 National Instruments Corporation l 7 Index interface management lines A 3 Microsoft Visual Basic programming instructions 3 13 Microsoft Visual C C programming instructions 3 12 Microsoft Windows See Windows Me 98 95 Windows 2000 NT multi device NI 488 2 calls See NI 488 2 calls multiple interfaces or multiple devices 3 5 multithreaded Win32 GPIB applications writing 7 9 to 7 10 n execute previous function n times function Interactive Control utility 6 10 n execute function n times function Interactive Control utility 6 10 National Instruments Web support F 1 NDAC not data accepted line table A 3 NI Developer Zone F 1 NI 488 2 calls device level calls and bus management 7 11 examples in Interactive Control utility 6 1 to 6 4 Interactive Control utility syntax board level calls table 6 7 to 6 8 device level traditional calls table 6 5 to 6 6 multi device calls table 6 8 to 6 9 monitoring recording and displaying 2 8 to 2 9 parallel polling device level traditional calls 7 18 to 7 19
56. Unicode versions are named ibbnaW ibfindw ibrdfw and ibwrt w You can use either the Unicode or ASCII versions of these functions with Windows 2000 NT but only the ASCII versions with Windows Me 98 95 In addition to pointers to the status variables and a handle to the loaded gpib 32 d11 you must define the direct entry prototypes for the functions you use in your application For the prototypes for each function exported by gpib 32 d11 refer to the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual The direct entry sample programs illustrate how to use direct entry to access gpib 32 d11 For more information about direct entry refer to the online help for your development environment Directly Accessing the gpib 32 dll Exports Make sure that the following lines are included at the beginning of your application ifdef _ cplusplus extern Cc endif include lt windows h gt include decl 32 h ifdef cplusplus endif NI 488 2 User Manual for Windows 3 14 ni com Chapter 3 Developing Your NI 488 2 Application In your Win32 application you need to load gpib 32 d11 before accessing the gpib 32 d11 exports The following code fragment shows you how to call the LoadLibrary function to load gpib 32 d11 and check for an error HINSTANCE Gpib32Lib NULL Gpib32Lib LoadLibrary GPIB 32 DLL if Gpib32Lib NULL r
57. agement Lines Five hardware lines manage the flow of information across the bus Table A 2 summarizes the GPIB interface management lines Table A 2 GPIB Interface Management Lines Line Description ATN attention Controller drives ATN true when it sends commands and false when it sends data messages IFC interface clear System Controller drives the IFC line to initialize the bus and make itself CIC REN remote enable System Controller drives the REN line to place devices in remote or local program mode SRQ service request Any device can drive the SRQ line to asynchronously request service from the Controller EOI end or identify Talker uses the EOI line to mark the end of a data message Controller uses the EOI line when it conducts a parallel poll National Instruments Corporation A 3 NI 488 2 User Manual for Windows Status Word Conditions This appendix gives a detailed description of the conditions reported in the status word ibsta For information about how to use ibsta in your application program refer to the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual Each bit in ibsta can be set for device calls dev board calls brd or both dev brd Table B 1 shows the status word layout Table B 1 Status Word Layout
58. alls table 6 8 to 6 9 numbers 6 4 strings 6 4 to 6 5 interface management lines A 3 interrupts autopolling and interrupts 7 14 enabling in Windows Me 98 95 D 4 to D 5 L LACS status word condition bit position hex value and type table 3 6 description B 5 Talker Listener applications 7 12 language interfaces 3 3 listen address A 2 Listeners A 1 See also Talker Listener applications LOK status word condition bit position hex value and type table 3 6 description B 3 manual See documentation Measurement amp Automation Explorer 2 1 to 2 16 accessing additional help and resources 2 14 National Instruments GPIB Web site 2 14 NI 488 2 online help 2 14 adding new GPIB interface 2 4 to 2 5 ni com changing GPIB device templates 2 12 to 2 13 Windows Me 98 95 2 12 Windows 2000 NT 2 12 communicating with instrument 2 6 to 2 8 deleting GPIB interface 2 5 enabling disabling NI 488 2 DOS support 2 13 to 2 14 Windows Me 98 95 2 13 Windows 2000 NT 2 13 to 2 14 getting started 2 2 to 2 3 monitoring recording and displaying NI 488 2 calls 2 8 to 2 9 overview 2 1 scanning for GPIB instruments 2 5 to 2 6 starting 2 2 troubleshooting NI 488 2 problems 2 4 viewing GPIB instrument information 2 11 to 2 12 viewing NI 488 2 software version 2 8 viewing or changing GPIB ENET network settings 2 15 to 2 16 assigning IP address 2 15 configuring advance IP settings 2 15 updating GPIB ENE
59. ant to use the Interactive Control utility to communicate with your instruments interactively by typing individual commands rather than issuing them from an application You can also use the Interactive Control utility to learn to communicate with your instruments using the NI 488 2 API For specific device communication instructions refer to the documentation that came with your instrument For information about using the Interactive Control utility and detailed examples refer to Chapter 6 Interactive Control Utility NI 488 2 User Manual for Windows 3 2 ni com Chapter 3 Developing Your NI 488 2 Application For advanced interactive communication with GPIB instruments use the Interactive Control utility as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB interface and select Interactive Control from the drop down menu that appears 4 At the command prompt type NI 488 2 API calls to communicate interactively with the your instrument For example you might use ibdev ibclr ibwrt ibrd and ibonl To view the online help for Interactive Control type he 1p at the Interactive Control command prompt For more information refer to Chapter 6 Interactive Control Utility Choosing Your Programming Methodology Based on your developmen
60. ation section in About This Manual Termination Method You should be aware of the data termination method that your device uses By default your NI 488 2 software is configured to send EOI on writes and terminate reads on EOI or a specific byte count If you send a command string to your device and it does not respond it might not be recognizing the end of the command In that case you need to send a termination message such as lt CR gt lt LF gt after a write command as follows ibwrt dev COMMAND x0A x0D 9 Other Errors If you experience other errors in your application refer to the NI 488 2 online help It includes extensive troubleshooting information and the answers to frequently asked questions For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual National Instruments Corporation 4 5 NI 488 2 User Manual for Windows NI Spy Utility This chapter introduces you to NI Spy a utility that monitors and records multiple National Instruments APIs for example NI 488 2 and VISA Overview NI Spy monitors records and displays the NI 488 2 calls made from Win32 Win16 and DOS NI 488 2 applications It is a useful tool for troubleshooting errors in your application and for verifying that the communication with your GPIB instrument is correct Starting NI Spy To start NI Spy complete the following steps 1 Select Start Progra
61. ation Explorer Basic Communication Query Write Read To establish basic communication with your instrument use the NI 488 2 Communicator as follows 1 If you have not already done so scan for connected instruments as described in the previous section Scan for GPIB Instruments 2 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 3 Expand the Devices and Interfaces directory by clicking on the next to the folder 4 Select your GPIB interface Measurement amp Automation Explorer displays the connected instruments in the right window pane 5 Right click on your GPIB instrument and select Communicate with Instrument from the drop down menu that appears The NI 488 2 Communicator dialog box appears as shown in Figure 2 4 yr NI 488 2 Communicator GPIBO Instrument 0 Primary Address 1 Globals m Status 5 Saar pony ibsta 0x100 zy H Aa Query Write Read iberr None END 5 ibentl 4 SHAI Configured POS String Received CMPL HOK HEA GE Show Sample Exit Figure 2 4 NI 488 2 Communicator 6 Type acommand in the Send String field and do one of the following e To write a command to the instrument then read a response back click on the Query button e To write a command to the instrument click on the Write button e To read a response from the instrument click on the Read button To view sa
62. bit pattern 0110 0110 or hex 66 to ibppc include decl 32 h char ppr dev ibdev 0 3 0 T3s 1 0 ibppc dev 0x66 If the GPIB interface configures itself for a parallel poll you should still use the ibppc function Pass the interface index or an interface unit descriptor value as the first argument in ibppc Also if the individual status bit ist of the interface needs to be changed use the ibist function In the following example the GPIB interface is to configure itself to participate in a parallel poll It asserts DIOS when ist is 1 if a parallel poll is conducted ibppe 0 Ox6C ibist 0 1 2 Conduct the parallel poll using ibrpp and check the response for a certain value The following example code performs the parallel poll and compares the response to hex 10 which corresponds to DIOS If that bit is set the ist of the device is 1 ibrpp dev amp ppr if ppr amp 0x10 printf ist 1 n 3 Unconfigure the device for parallel polling with ibppc Notice that any value having the parallel poll disable bit set bit 4 in the bit pattern disables the configuration so you can use any value between hex 70 and 7E ibppc dev 0x70 NI 488 2 User Manual for Windows 7 18 ni com Chapter 7 NI 488 2 Programming Techniques Parallel Polling with Multi Device NI 488 2 Calls Complete the following steps to implement parallel polling the using multi device NI 488 2 calls Each step contains example
63. ble 6 1 Tables 6 1 and 6 2 summarize the syntax of the traditional NI 488 2 calls in the Interactive Control utility Table 6 3 summarizes the syntax of the multi device NI 488 2 calls in the Interactive Control utility Table 6 4 summarizes the auxiliary functions that you can use in the Interactive Control utility For more information about the function parameters use the online help available by typing in help If you enter only the function name the Interactive Control utility prompts you for parameters Syntax for Device Level Traditional NI 488 2 Calls in Interactive Control Syntax Description ibask option Return configuration information where option is a mnemonic for a configuration parameter ibbna bname Change access interface of device where bname is symbolic name of new interface ibelr Clear specified device ibconfig option value Alter configurable parameters where option is mnemonic for a configuration parameter ibdev BdIndx pad sad tmo eot eos Open an unused device ibdev parameters are BdIndx pad sad tmo eot eos National Instruments Corporation 6 5 NI 488 2 User Manual for Windows Chapter 6 Interactive Control Utility Table 6 1 Syntax for Device Level Traditional NI 488 2 Calls in Interactive Control Continued Syntax Description ibeos v Change disable EOS message ibeot v Enable disable END message ibln pad sad Check for presence o
64. cal National Instruments Corporation 5 3 NI 488 2 User Manual for Windows Interactive Control Utility This chapter introduces you to the Interactive Control utility which lets you communicate with GPIB devices interactively Overview With the Interactive Control utility you communicate with the GPIB devices through functions you interactively type in at the keyboard For specific information about communicating with your particular device refer to the documentation that came with the device You can use the Interactive Control utility to practice communication with the instrument troubleshoot problems and develop your application The Interactive Control utility helps you to learn about your instrument and to troubleshoot problems by displaying the following information on your screen after you enter a command e Results of the status word ibsta in hexadecimal notation e Mnemonic constant of each bit set in ibsta e Mnemonic value of the error variable iberr if an error exists the ERR bit is set in ibsta e Count value for each read write or command function e Data received from your instrument Getting Started with Interactive Control This section shows you how to use the Interactive Control utility to test a sequence of NI 488 2 calls To start the Interactive Control utility complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Meas
65. ccurred When an error occurs the error type is specified by iberr To check for an NI 488 2 error use the following statement after each NI 488 2 call if ibsta amp ERR printf NI 488 2 error d encountered iberr B Note The value in iberr is meaningful as an error type only when the ERR bit is set in ibsta indicating that an error has occurred For more information about error codes and solutions refer to Chapter 4 Debugging Your Application or Appendix C Error Codes and Solutions Count Variables ibent and ibcntl The count variables are updated after each read write or command function In Win32 applications ibcnt and ibcnt1 are 32 bit integers On some systems like MS DOS ibcnt is a 16 bit integer and ibent1 is a 32 bit integer For cross platform compatibility all applications should use ibcnt1 If you are reading data the count variables indicate the number of bytes read If you are sending data or commands the count variables reflect the number of bytes sent Using Interactive Control to Communicate with Devices Before you begin writing your application you might want to use the Interactive Control utility to communicate with your instruments interactively by typing in commands from the keyboard rather than from an application You can use the Interactive Control utility to learn to communicate with your instruments using the NI 488 2 API For specific device communication instructions refer to the u
66. cing the SRQ line to be asserted e A cable problem might exist involving the SRQ line Although the occurrence of ESRQ warns you of a definite GPIB problem it does not affect GPIB operations except that you cannot depend on the ibsta RQS bit while the condition lasts Check to see if other devices not used by your application are asserting SRQ Disconnect them from the GPIB if necessary Solutions ETAB occurs only during the FindLstn and FindrRQs functions ETAB indicates that there was some problem with a table used by these functions e In the case of FindLstn ETAB means that the given table did not have enough room to hold all the addresses of the Listeners found e Inthe case of FindRQS ETAB means that none of the devices in the given table were requesting service In the case of FindLstn increase the size of result arrays In the case of FindRQs check to see if other devices not used by your application are asserting SRQ Disconnect them from the GPIB if necessary National Instruments Corporation C 9 NI 488 2 User Manual for Windows Windows Me 98 95 Troubleshooting and Common Questions This appendix describes how to troubleshoot problems and answers some common questions about the NI 488 2 software for Windows Me 98 95 Troubleshooting EDVR Error Conditions In some cases NI 488 2 calls may return with the ERR bit set in ibsta and the value EDVR in iberr The value stored in ibcnt1 is useful in tro
67. code 1 Configure the device for parallel polling using the PPo11Config call unless the device can configure itself for parallel polling The following example configures a device at address 3 to assert data line 5 DIO5 when its ist value is 1 include decl 32 h char response Addr4882_ t AddressList 2 The following command clears the GPIB SendIFC 0 The value of sense is compared with the ist bit of the device and determines whether the data line is asserted PPollConfig 0 3 5 1 2 Conduct the parallel poll using PPo11 store the response and check the response for a certain value In the following example because DIOS is asserted by the device if ist is 1 the program checks bit 4 hex 10 in the response to determine the value of ist PPoll 0 amp response If response has bit 4 hex 10 set the ist bit of the device at that time is equal to 1 If it does not appear the ist bit is equal to 0 Check the bit in the following statement if response amp 0x10 printf The ist equals 1 n else printf The ist equals 0 n 3 Unconfigure the device for parallel polling using PPol1Unconf ig as shown in the following example In this example the NOADDR constant must appear at the end of the array to signal the end of the address list If NOADDR is the only value in the array all devices receive the parallel poll disable message AddressList 0 3 AddressList 1
68. ctually use the transferred data could become corrupted If you specify a cable length longer than what you actually use the data is transferred successfully but more slowly than if you specified the correct cable length In addition to using ibconfig to configure your GPIB interface for HS488 the Controller In Charge must send out GPIB command bytes interface messages to configure other devices for HS488 transfers NI 488 2 User Manual for Windows 7 2 ni com Chapter 7 NI 488 2 Programming Techniques If you are using device level calls the NI 488 2 software automatically sends the HS488 configuration message to devices If you enabled the HS488 protocol in the NI 488 2 Configuration utility the NI 488 2 software sends out the HS488 configuration message when you use ibdev to bring a device online If you call ibconfig to change the GPIB cable length the NI 488 2 software sends out the HS488 message again the next time you call a device level function If you are using board level traditional NI 488 2 calls or multi device NI 488 2 calls and you want to configure devices for high speed you must send the HS488 configuration messages using ibcmd or SendCmds The HS488 configuration message is made up of two GPIB command bytes The first byte the Configure Enable CFE message hex 1F places all HS488 devices into their configuration mode Non HS488 devices should ignore this message The second byte is a GPIB secondary command that
69. ddress to 16 hexadecimal 22 decimal Decimal numbers Enter the number only For example ibpad 22 sets the primary address to 22 decimal You can enter strings as an ASCII character sequence hex bytes or special symbols ASCII character sequence You must enclose the entire sequence in quotation marks Hex byte You must use a backslash character and an x followed by the hex value For example hex 40 is represented by x40 NI 488 2 User Manual for Windows 6 4 ni com Address Syntax Chapter 6 Interactive Control Utility Special symbols Some instruments require special termination or end of string EOS characters that indicate to the device that a transmission has ended The two most common EOS characters are r and n r represents a carriage return character and n represents a linefeed character You can use these special characters to insert the carriage return and linefeed characters into a string as in IDN r n Some of the NI 488 2 calls have an address or address list parameter An address is a 16 bit representation of the GPIB device address The primary address is stored in the low byte and the secondary address if any is stored in the high byte For example a device at primary address 6 and secondary address 0x67 has an address of 0x6706 A NULL address is represented as Oxffff An address list is represented by a comma separated list of addresses such as 1 2 3 Interactive Control Commands Ta
70. disabling NI 488 2 DOS support 2 13 to 2 14 running existing DOS NI 488 2 applications 3 17 troubleshooting and common questions D 1 to D 8 common questions D 5 to D 8 Device Manager device status code D 3 EDVR error conditions D 1 to D 2 enabling interrupts D 4 to D 5 viewing or changing settings GPIB ENET network 2 15 to 2 16 GPIB ENET 100 network 2 16 to 2 17 GPIB interface 2 9 to 2 10 ni com Index Windows 2000 NT autopolling and interrupts 7 14 changing GPIB device templates 2 13 enabling disabling NI 488 2 DOS support 2 13 to 2 14 running existing DOS NI 488 2 applications 3 18 troubleshooting and common questions E 1 to E 3 viewing or changing GPIB interface settings 2 10 to 2 11 Worldwide technical support F 2 National Instruments Corporation l 11 NI 488 2 User Manual for Windows
71. dows 2000 NT 3 18 Chapter 4 Debugging Your Application NI SPY ronnen arani ea ao need nse desta di geste line nets nla een alee Renton aes ied 4 1 Global Stattis Variables nerens aa e ovaveacitd dovesseutsa cde sovstcaedevs 4 2 Existing Applicat ONS nen eos rese EE E este nssu ste abse restore vis rasubnerte eevee terete 4 3 NI 488 2 Error Codes siana sovsa soak eves cdvedevesuasea a a a A os 4 3 Configuration ELLOS niens ao aE A E a a aa a a a uate 4 3 Timing ErTOLS seere a a a A A 4 4 ComMuUMniGation EOT S a a a Paced e a a a a aae aia aiaa 4 5 Repeat Addressing motite a avis deat elie eda E 4 5 Termination Method baserriaren n E ER E cone 4 5 CHET Eh a0 oE E EEE S AE EES E E heteees 4 5 Chapter 5 NI Spy Utility OVEIVIEW oee e E E E rte RRR aon RE EE A A EAEN 5 1 Statne NESPY r oes suey es ee RA ee aed tees SE aed 5 1 Using the NI Spy Online Helpi tseremoonia r tides E RORO RR 5 2 Locating Errors with NI SPY sosaiete arara aee iaaa EEES EA AEE 5 2 Viewing Properties for Recorded Calls ssesesseesseessseeeresrssesrssesresrsresresrsresrerenesresrses 5 2 Exiting NIS peia a E a E AO AE 5 3 Performance Consid rationSosirss siirinsesi a E E E EE RER ERER 5 3 Chapter 6 Interactive Control Utility OVENI EW a one e Aa e A E E eee ees 6 1 Getting Started with Interactive Control eect eee ceeceeeeseceseeseeeseeaeeeeeaeenseeseeseenaes 6 1 Interactive Control Syntax oiron ekse er eeta e aaa ASS R ENEE A aR 6 4 Number S
72. e GPIB cable is disconnected For a detailed list of the error codes and their meanings refer to Chapter 4 Debugging Your Application Count Information When an I O function completes the Interactive Control utility displays the actual number of bytes sent or received regardless of the existence of an error condition If one of the addresses in an address list is invalid then the error is EARG and the Interactive Control utility displays the index of the invalid address as the count The count has a different meaning depending on which NI 488 2 call is made For the correct interpretation of the count return refer to the function descriptions in the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual National Instruments Corporation 6 11 NI 488 2 User Manual for Windows NI 488 2 Programming Techniques This chapter describes techniques for using some NI 488 2 calls in your application For more information about each function refer to the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual Termination of Data Transfers GPIB data transfers are terminated either when the GPIB EOI line is asserted with the last byte of a transfer or when a preconfigured end of string EOS character is transmitted By default EOI is asserted wi
73. e the following steps 1 Make sure that no older version of the NI 488 2 DOS device driver is being loaded from your config sys file To do so complete the following steps Locate your config sys file and open it for editing b Find the following line device lt path gt gpib com where lt paths refers to the drive and directory where gpib com is located c If that line appears type REM at the beginning of the line as follows REM device lt path gt gpib com d Save your config sys file and close it 2 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 3 Expand the Devices and Interfaces directory by clicking on the next to the folder 4 Click on your GPIB interface and select Tools NI 488 2 DOS Support from the Explorer menu 5 Enable or disable DOS support in the NI 488 2 Settings dialog box and click on the OK button 6 If you are prompted to do so restart your system National Instruments Corporation 2 13 NI 488 2 User Manual for Windows Chapter 2 Measurement amp Automation Explorer Windows 2000 NT To enable NI 488 2 DOS support in Windows 2000 NT complete the following steps 1 Open your config nt file located in the Windows NT system32 directory for example c windows system32 2 Find the following lines REM To run DOS GPIB applications uncomment the REM following line REM device lt path
74. eList int WaitResult WaitSRQ 0 amp WaitResult if WaitResult printf SRQ is asserted n AllSpoll 0 AddrList ResponseList if ibsta amp ERR for i 0 AddrList i NOADDR i printf Device at pad x returned byte x n AddrList i ResponseList i NI 488 2 User Manual for Windows 7 16 ni com Chapter 7 NI 488 2 Programming Techniques return Parallel Polling Although parallel polling is not widely used it is a useful method for obtaining the status of more than one device at the same time The advantage of parallel polling is that a single parallel poll can easily check up to eight individual devices at once In comparison eight separate serial polls would be required to check eight devices for their serial poll response bytes The value of the individual status bit ist determines the parallel poll response Implementing a Parallel Poll You can implement parallel polling with either the traditional or multi device NI 488 2 calls If you use multi device NI 488 2 calls to execute parallel polls you do not need extensive knowledge of the parallel polling messages However you should use the traditional NI 488 2 calls for parallel polling when the GPIB interface is not the Controller and the interface must configure itself for a parallel poll and set its own individual status bit ist Parallel Polling with Traditional NI 488 2 Calls Complete the following steps to
75. ear SDC command has been sent by another Controller If you use the ibwait or ibnotify function to wait for DCAS and the wait is completed DCAS is cleared from ibsta after the next NI 488 2 call The same is true of reads and writes If you call a read or write function such as ibwrt or Send and DCAS is set in ibsta the I O operation is aborted DCAS is cleared from ibsta after the next NI 488 2 call National Instruments Corporation B 5 NI 488 2 User Manual for Windows Error Codes and Solutions This appendix lists a description of each error some conditions under which it might occur and possible solutions Table C 1 lists the GPIB error codes Table C 1 GPIB Error Codes Error iberr Mnemonic Value Meaning EDVR 0 System error ECIC 1 Function requires GPIB interface to be CIC ENOL 2 No Listeners on the GPIB EADR 3 GPIB interface not addressed correctly EARG 4 Invalid argument to function call ESAC 5 GPIB interface not System Controller as required EABO 6 T O operation aborted timeout ENEB 7 Nonexistent GPIB interface EDMA 8 DMA error EOIP 10 Asynchronous I O in progress ECAP 11 No capability for operation EFSO 12 File system error EBUS 14 GPIB bus error ESTB 15 Serial poll status byte queue overflow ESRQ 16 SRQ stuck in ON position ETAB 20 Table problem National Instruments Corporation C 1 NI 488 2 User Manual for Windows Appendi
76. easurement amp Automation Explorer select Start Programs National Instruments NI 488 2 Explore GPIB Overview You can perform the following GPIB related tasks in Measurement amp Automation Explorer e Establish basic communication with your GPIB instruments e Scan for instruments connected to your GPIB interface e Launch the NI 488 2 Getting Started Wizard to get started with GPIB instrument communication e Launch the NI 488 2 Troubleshooting Wizard to troubleshoot GPIB and NI 488 2 problems e Launch NI Spy to monitor NI 488 2 or VISA API calls to GPIB interfaces e View information about your GPIB hardware and NI 488 2 software e Reconfigure the GPIB interface settings e Locate additional help resources for GPIB and NI 488 2 National Instruments Corporation 2 1 NI 488 2 User Manual for Windows Chapter 2 Measurement amp Automation Explorer Starting Measurement amp Automation Explorer To start Measurement amp Automation Explorer select Start Programs National Instruments NI 488 2 Explore GPIB Figure 2 1 shows Measurement amp Automation Explorer E MAX dol x File Edit View Tools Help ee National Instruments evices and Interfaces E Software Measurement amp Automation Explorer A What is Measurement amp About MAX Help Automation Explorer i i MAX displays an interactive task listin the right side of the MAX window to
77. eee eeeeeeeeseeeeeeeeeees 3 7 Programming Modelit eaa oA E E E E dt ecaesstevete eeseapaes 3 8 Applications That Communicate with a Single GPIB Device 3 8 Items to Include e e na a Wena e ea E E ER aii 3 8 General Program Steps and Examples ssssseesssereseseserreersersrreeseee 3 8 Applications That Use Multiple Interfaces or Communicate with M ltiple GPIB Devices iain e ERE AN AE cava dies 3 10 Items to nelidae o a EE p E E ENO R E 3 10 General Program Steps and Examples sseesseeeseeresssrsrrerereerrsesreees 3 10 Language Specific Programming Instructions cee eeceeseeeeeeeeeeeseceeeeseenseeseeeaes 3 12 Microsoft Visual C C Version 2 0 or Later ccccccsccecesseeeeseeeeeneeeeseees 3 12 Borland C C Version 4 0 or Later ccccccecessccssssccessecessseeeesseeesseeesnees 3 13 Visual Basic Version 4 0 or Later cccccecesseeesseeceeseeeeesseeesseeeesseeeensseeese 3 13 Direct Entry with Cec eccsees tecec a eel dehestew teres 3 13 gpib 32 dl EX ports sstied cist e dedi iat 3 13 Directly Accessing the gpib 32 dI Exports eee eee eeeeeees 3 14 NI 488 2 User Manual for Windows vi ni com Contents Running Existing NI 488 2 Applications 2 0 0 0 eee eeeeseeeeceeceeeeseceeeeseeeeeaeseeeeaeesaes 3 17 Running Existing Win32 and Win16 NI 488 2 Applications 0 ee 3 17 Running Existing DOS NI 488 2 Applications Under Windows Me 98 95 3 17 Running Existing DOS NI 488 2 Applications under Win
78. eeeeseeeeeseseenaes 2 8 View or Change GPIB Interface Settings eee e eee ese eeseeseceseeeeeseeseesaeeseeeaeeneeeaes 2 9 WindOwsi Me 98 95 wis svesiscck ccosneeicvcss en saves coseeseeeivesdevetinadvevstivatubea teres toesutecesa doves 2 9 Windows 2OQO NT sess cecescsossegedsds lusgeetdsesvevssudcedesuveeisidesevstehesvasvspedees sevsecladeseee 2 10 View GPIB Instrument Information ccccccccccsssscccceeseseeeceesessceeceeessssceccesessseeeeees 2 11 Change GPIB Device Templates 0 0 ees ceeeeseeseeeseeseceseeseesseeaeeeeeaeeneeeaeseeeeaeenaes 2 12 WitidOws Me 98 95 a a ae doe 04 oak ET ES 2 12 Windows 2O00 NT an a r seca svsuwaesaeds r 2 12 Enable Disable NI 488 2 DOS Support cece eeeseseeeeecseeeseesecesecseeesesaesneeeaeenaes 2 13 Windows M 98 95 tinn n ann na a a aa ae 2 13 Windows 20Q00 NI rrsan e EE e a E E E EATE EN 2 14 National Instruments Corporation v NI 488 2 User Manual for Windows Contents Access Additional Help and ReSources cescessccssceeseceseeeseeceaeeeeessaeeeaeeeeeeseaeeeneeeeas 2 14 NI 488 2 Online Helps asia nii desssseateeoti sadeeess 2 14 National Instruments GPIB Web Site oo ee eceeeeeseesseeneceeeeaeeneeeaeeneeeaes 2 14 View or Change GPIB ENET Network Settings Windows Me 98 95 Only 2 15 Assign IP Addres Srnice rai ea cued svtea daa sp RE a e s 2 15 Configure Advanced IP Settings eee cecesesseesseeseeseeeseeneeeseceeenseeeeeeaee 2 15 Update GPIB ENET Firmware
79. en determine which device asserted the SRQ line and respond accordingly The most common method for SRQ detection and servicing is the serial poll This section describes how to set up your application to detect and respond to service requests from GPIB devices Service Requests from IEEE 488 Devices TIEFE 488 devices request service from the GPIB Controller by asserting the GPIB SRQ line When the Controller acknowledges the SRQ it serial polls each open device on the bus to determine which device requested service Any device requesting service returns a status byte with bit 6 set and then unasserts the SRQ line Devices not requesting service return a status byte with bit 6 cleared Manufacturers of IEEE 488 devices use lower order bits to communicate the reason for the service request or to summarize the state of the device Service Requests from IEEE 488 2 Devices The IEEE 488 2 standard refined the bit assignments in the status byte In addition to setting bit 6 when requesting service IEEE 488 2 devices also use two other bits to specify their status Bit 4 the Message Available bit MAV is set when the device is ready to send previously queried data Bit 5 the Event Status bit ESB is set if one or more of the enabled IEEE 488 2 events occurs These events include power on user request command error execution error device dependent error query error request control and operation complete The device can assert SRQ when ESB
80. es and used to manage the GPIB Input output In this manual it is the transmission of commands or messages between the system via the GPIB board and other devices on the GPIB The address of the GPIB board from the point of view of the CPU as opposed to the GPIB address of the GPIB board Also called port address or board address NI 488 2 User Manual for Windows G 4 ni com ISA ist L LAD language interface Listener LLO low level function MAV MLA MSA MTA multitasking National Instruments Corporation G 5 Glossary Industry Standard Architecture An Individual Status bit of the status byte used in the Parallel Poll Configure function Listen Address See MLA Code that enables an application program that uses NI 488 2 calls to access the driver A GPIB device that receives data messages from a Talker Local Lockout The GPIB command used to tell all devices that they may or should ignore remote GPIB data messages or local front panel controls depending on whether the device is in local or remote program mode A rudimentary board or device function that performs a single operation Meters The Message Available bit is part of the IEEE 488 2 defined status byte which is received from a device responding to a serial poll My Listen Address A GPIB command used to address a device to be a Listener It can be any one of the 31 primary addresses My Secondary Address The GPIB
81. es from multiple threads of execution You can avoid this problem in two ways e Use synchronization to protect access to process global variables e Do not use process global variables If you choose to implement the synchronization solution you must ensure that the code making NI 488 2 calls and examining the NI 488 2 globals modified by a NI 488 2 call is protected by a synchronization primitive For example each thread might acquire a semaphore before making a NI 488 2 call and then release the semaphore after examining the NI 488 2 globals National Instruments Corporation 7 9 NI 488 2 User Manual for Windows Chapter 7 NI 488 2 Programming Techniques modified by the call For more information about the use of synchronization primitives refer to the documentation about using Win32 synchronization objects that came with your development tools If you choose not to use process global variables you can access per thread copies of the NI 488 2 global variables using a special set of NI 488 2 calls Whenever a thread makes a NI 488 2 call the driver keeps a private copy of the NI 488 2 globals for that thread The driver keeps a separate private copy for each thread The following code shows the set of functions you can use to access these per thread NI 488 2 global variables int ThreadIbsta int ThreadIberr return thread specific iberr int ThreadIbcnt long ThreadIbentl1 return thread specific ibcntl return t
82. eturn FALSE For the prototypes for each function refer to the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual For functions that return an integer value like ibdev or ibwrt the pointer to the function needs to be cast as follows int _stdcall Pname where Pname is the name of the pointer to the function For functions that do not return a value like FindLstn or SendList the pointer to the function needs to be cast as follows void _stdcall Pname where Pname is the name of the pointer to the function They are followed by the function s list of parameters as described in the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual Following is an example of how to cast the function pointer and how the parameter list is set up for ibdev and ibon1 functions int _stdcall Pibdev int ud int pad int sad int tmo int eot int eos int _stdcall Pibonl int ud int v Next your Win32 application needs to use Get ProcAddress to get the addresses of the global status variables and functions your application needs The following code fragment shows you how to get the addresses of the pointers to the status variables and any functions your application needs Pointers to NI 488 2 global status variables int Pibsta int
83. f device on the GPIB at pad sad ibloc Go to local ibonl v Place device online or offline ibpad v Change primary address ibpet Pass control ibppe v Parallel poll configure ibrd count Read data where count is the bytes to read ibrda count Read data asynchronously where count is the bytes to read ibrdf flname Read data to file where 1name is pathname of file to read ibrpp Conduct a parallel poll ibrsp Return serial poll byte ibsad v Change secondary address ibstop Abort asynchronous operation ibtmo v Change disable time limit ibtrg Trigger selected device ibwait mask Wait for selected event where mask is a hex or decimal integer or a list of mask bit mnemonics such as ibwait TIMO CMPL ibwrt wrtbuf Write data ibwrta wrtbuf Write data asynchronously ibwrtf flname Write data from a file where 1name is pathname of file to write NI 488 2 User Manual for Windows 6 6 ni com Chapter 6 Interactive Control Utility Table 6 2 Syntax for Board Level Traditional NI 488 2 Calls in Interactive Control Syntax Description ibask option Return configuration information where option is a mnemonic for a configuration parameter ibcac v Become active Controller ibemd cmdbuf Send commands ibcmda cmdbuf Send commands asynchronously ibconfig option Alter configurable parameters where option is mnemonic for a value con
84. figuration parameter ibdma v Enable disable DMA ibeos v Change disable EOS message ibeot v Enable disable END message ibfind udname Return unit descriptor where udname is the symbolic name of interface for example gpibo ibgts v Go from Active Controller to standby ibist v Set clear ist iblines Read the state of all GPIB control lines ibln pad sad Check for presence of device on the GPIB at pad sad ibloc Go to local ibonl v Place device online or offline ibpad v Change primary address ibppe v Parallel poll configure ibrd count Read data where count is the bytes to read ibrda count Read data asynchronously where count is the bytes to read ibrdf flname Read data to file where 1name is pathname of file to read ibrpp Conduct a parallel poll ibrsc v Request release system control ibrsv v Request service ibsad v Change secondary address National Instruments Corporation 6 7 NI 488 2 User Manual for Windows Chapter 6 Interactive Control Utility Table 6 2 Syntax for Board Level Traditional NI 488 2 Calls in Interactive Control Continued Syntax Description ibsic Send interface clear ibsre v Set clear remote enable line ibstop Abort asynchronous operation ibtmo v Change disable time limit ibwait mask Wait for selected event where mask is a hex or decimal integer or a list of mask bit mnemonics such as ibwait TIMO CMPL ibwrt wrtb
85. for Windows ECIC is returned when one of the following board functions is called while the interface is not CIC Any device level traditional NI 488 2 calls that affect the GPIB Any board level traditional NI 488 2 calls that issue GPIB command bytes ibemd ibcmda ibln and ibrpp C 2 ni com Solutions Appendix C Error Codes and Solutions ibcac and ibgts Any NI 488 2 multi device calls that issue GPIB command bytes SendCmds PPoll Send and Receive Possible solutions for this error are as follows ENOL 2 Use ibsic or SendIFC to make the GPIB interface become CIC on the GPIB Use ibrsc 1 to make sure your GPIB interface is configured as System Controller In multiple CIC situations always be certain that the CIC bit appears in the status word ibsta before attempting these calls If it does not appear you can perform an ibwait for CIC call to delay further processing until control is passed to the interface ENOL usually occurs when a write operation is attempted with no Listeners addressed For a device write ENOL indicates that the GPIB address configured for that device in the software does not match the GPIB address of any device connected to the bus that the GPIB cable is not connected to the device or that the device is not powered on ENOL can occur in situations where the GPIB interface is not the CIC and the Controller asserts ATN before the write call in progress has ended Solutions Pos
86. g steps to free up an interrupt resource and configure your GPIB interface to use the available interrupt resource Step 1 Free up an Interrupt Resource To free up an interrupt resource you must remove or disable one of the other devices in your system If possible remove a device in your system However your system typically does not have any devices that can be removed In this case you should disable a device that you do not use such as LPT1 or COM1 To do so complete the following steps 1 Select Start Settings Control Panel 2 Double click on the System icon 3 Select the Device Manager tab and click on the View devices by type button If you do not use your LPT port you can disable the LPT1 device and if you do not use your COM port you can disable the COM1 device However do not disable a device that your system is using You only need to disable one device either LPT1 or COM1 4 Double click on the Ports COM amp LPT item If the device you want to disable has a yellow exclamation mark 1 overlaid on it the device is not working properly and does not have assigned resources Disabling a device that is not working properly does not free up an interrupt resource 5 Double click on the device that you want to disable Communications Port COM1 or Printer Port LPT1 6 Inthe Properties dialog box check the Disable in this hardware profile checkbox If you are using Windows 95 version A uncheck the O
87. ger 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB interface and select Delete Interface from the drop down menu that appears 4 When prompted click on the Yes button to confirm the removal of your interface Scan for GPIB Instruments To scan for instruments connected to your GPIB interface or to add a new instrument to your system complete the following steps 1 Make sure that your instrument is powered on and connected to your GPIB interface 2 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 3 Expand the Devices and Interfaces directory by clicking on the next to the folder 4 Right click on your GPIB interface and select Scan for Instruments from the drop down menu that appears Measurement amp Automation Explorer displays the connected instruments in the right window pane National Instruments Corporation 2 5 NI 488 2 User Manual for Windows Chapter 2 Measurement amp Automation Explorer Instruments Not Found Ifthe Instruments not Found message appears in the right window pane Measurement amp Automation Explorer did not find any instruments To solve this problem make sure that your GPIB instruments are powered on and properly connected to
88. ghtly but it remains a significant problem for all transfers under 1 Mbyte For instructions on how to assign an interrupt to your GPIB interface if one was not assigned refer to the Enabling Interrupts section earlier in this appendix How can I determine if my GPIB hardware and the NI 488 2 software are installed properly Run the NI 488 2 Troubleshooting Wizard To do so select Start Programs National Instruments NI 488 2 Explore GPIB Then select Help Troubleshooting NI 488 2 Troubleshooting Wizard When should I use the Interactive Control utility You can use the Interactive Control utility to test and verify instrument communication troubleshoot problems and develop your application For more information refer to Chapter 6 Interactive Control Utility How do I use an NI 488 2 language interface For information about using NI 488 2 language interfaces refer to Chapter 3 Developing Your NI 488 2 Application What do I need to know to communicate properly with my GPIB instrument Refer to the documentation that came with your instrument The command sequences that you use depend on the specific instrument The documentation for each instrument should include the GPIB commands that you need to communicate with your instrument In most cases device level traditional NI 488 2 calls are sufficient for communicating with instruments For more information refer to Chapter 3 Developing Your NI 488 2 Application
89. h office Web sites provide up to date contact information support phone numbers e mail addresses and current events If you have searched the technical support resources on our Web site and still cannot find the answers you need contact your local office or National Instruments corporate Phone numbers for our worldwide offices are listed at the front of this manual NI 488 2 User Manual for Windows F 2 ni com Glossary Prefix Meaning Value n nano 10 m milli 10 3 M mega 106 acceptor handshake access board ANSI API ASCII asynchronous automatic serial polling base I O address BIOS board level function National Instruments Corporation G 1 Listeners use this GPIB interface function to receive data and all devices use it to receive commands See source handshake and handshake The GPIB board that controls and communicates with the devices on the bus that are attached to it American National Standards Institute Application Programming Interface American Standard Code for Information Interchange An action or event that occurs at an unpredictable time with respect to the execution of a program A feature of the GPIB software in which serial polls are executed automatically by the driver whenever a device asserts the GPIB SRQ line Also called autopolling See I O address Basic Input Output System A rudimentary function that performs a single operation
90. hange GPIB Interface Settings To view or change the settings of your GPIB interface refer to one of the following sections Windows Me 98 95 To view or change your interface settings in Windows Me 98 95 complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB interface and select Properties from the drop down menu that appears National Instruments Corporation 2 9 NI 488 2 User Manual for Windows Chapter 2 Measurement amp Automation Explorer 4 Windows 2000 NT The Properties dialog box appears Figure 2 6 shows the Properties dialog box for an AT GPIB TNT Plug and Play interface AT GPIB TNT Plug and Play Properties 29 x NI 488 2 Settings x AT GPIB TNT Plug and Play MISA PrP Serial Number 00003635 Interface Name m Termination Methods Ec I7 Send EDI at end of Write GPIB Address I Terminate Read on EOS EEN I Set EDI with EOS on Write fo x i I 8 bit EOS Compare Secondary NONE z 0 EOS Byte 1 0 Timeout 10sec E Advanced IV System Controller cot __ Figure 2 6 Properties Dialog Box in Windows Me 98 95 If you need more information about a field in the Properties dialog box click on the button in the upper right corner of the d
91. he NI 488 2 Configuration utility an EDVR error condition occurs with ibcnt1 set to OxE0140035 EDVR Error Condition with ibentl Set to 0xE0320029 533594071 or 0xE1050029 519765975 If a call is made with an interface number that is assigned to a GPIB interface that is unusable because of a resource conflict an EDVR error condition occurs with ibcnt1 set to 0OxE0320029 or 0xE1050029 This error is also returned if you remove a PCMCIA GPIB or PCMCIA GPIB while the driver is accessing it or if you try to access a PCMCIA GPIB when 32 bit PCMCIA drivers are not enabled To enable the 32 bit PCMCIA drivers complete the following steps 1 Select Start Settings Control Panel 2 Double click on the System icon 3 Select the Performance tab 4 Ifthe PC Cards PCMCIA line does not read 32 bit select Start Settings Control Panel and double click on the PC Card PCMCIA icon The PC Card PCMCIA Wizard enables the 32 bit PCMCIA drivers 5 Shut down your system and restart it Your system should detect your PCMCIA GPIB or PCMCIA GPIB interface EDVR Error Condition with ibentl Set to 0xE0140004 535560188 This error might occur if the GPIB interface has not been correctly installed and detected by Windows For instructions on how to install the GPIB hardware refer to the GPIB Hardware Guide on the NI 488 2 for Windows CD For instructions on accessing this manual refer to the Using the NI 488 2 Documentation section
92. hout interrupts but the NI 488 2 software performance is significantly slower without interrupts For example transfer sizes between and 10 bytes transfer at a rate of only 2 of the transfer rate with enabled interrupts As the transfer size increases the performance degradation decreases slightly but it remains a significant problem for all transfers under 1 Mbyte For instructions on how to assign an interrupt to your GPIB interface if one was not assigned refer to the Enabling Interrupts section in Appendix D Windows Me 98 95 Troubleshooting and Common Questions Windows 2000 NT The NI 488 2 software for Windows 2000 NT does not function properly if interrupts are disabled SRQ and Serial Polling with Device Level Traditional NI 488 2 Calls You can use the device level traditional NI 488 2 call ibrsp to conduct a serial poll ibrsp conducts a single serial poll and returns the serial poll response byte to the application If automatic serial polling is enabled the application can use ibwait to suspend program execution until RQS appears in the status word ibsta The program can then call ibrsp to obtain the serial poll response byte The following example shows you how to use the ibwait and ibrsp functions in a typical SRQ servicing situation when automatic serial polling is enabled include decl 32 h char GetSerialPollResponse int DeviceHandle NI 488 2 User Manual for Windows 7 14 ni com Chapter 7 NI 488 2 P
93. hread specific ibsta return thread specific ibcnt In your application instead of accessing the per process NI 488 2 globals substitute a call to get the corresponding per thread NI 488 2 global For example the following line of code if ibsta amp ERR could be replaced by if ThreadIbsta amp ERR A quick way to convert your application to use per thread NI 488 2 globals is to add the following define lines at the top of your C file define ibstaThreadIbsta define iberrThreadIberr define ibcntThreadIbcnt 1 define ibcntl1ThreadiIbent l 3 Note Ifyou are using ibnotify in your application see the Asynchronous Event Notification in Win32 NI 488 2 Applications section of this chapter the ibnotify callback is executed in a separate thread that is created by the NI 488 2 driver Therefore if your application makes NI 488 2 calls from the ibnot ify callback function and makes NI 488 2 calls from other places you must use the ThreadIbsta ThreadIberr ThreadIbcnt and ThreadIbcnt1 functions described in this section instead of the per process NI 488 2 globals NI 488 2 User Manual for Windows 7 10 ni com Chapter 7 NI 488 2 Programming Techniques Device Level Calls and Bus Management The device level traditional NI 488 2 calls are designed to perform all of the GPIB management for your application However the NI 488 2 driver can handle bus management only when the GPIB interface is CIC Contr
94. i Ogyad v Ww Website R K gt Explore CD O3 qo gt Exit Install and Launch LabVIEW Evaluation Q Install LabWindows CVI Evaluation A Install ComponentWorks Evaluation HQ Install HiQ Student Edition Figure 2 2 Viewing Documentation on Your CD The View Documentation Wizard helps you find the documentation that you want to view 2 Use the NI 488 2 Getting Started Wizard to verify the installation and establish basic communication with your GPIB instruments ays Note After you install the NI 488 2 software and restart your system the NI 488 2 Getting Started Wizard runs automatically To start it within Measurement amp Automation Explorer select Help Getting Started NI 488 2 Getting Started Wizard After you install the NI 488 2 software and your GPIB hardware you can run an existing NI 488 2 application or develop a new NI 488 2 application National Instruments Corporation 2 3 NI 488 2 User Manual for Windows Chapter 2 Measurement amp Automation Explorer Troubleshoot NI 488 2 Problems To troubleshoot NI 488 2 problems run the NI 488 2 Troubleshooting Wizard as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Select Help Troubleshooting NI 488 2 Troubleshooting Wizard The Troubleshooting Wizard tests your GPIB interface and displays the results as shown in Figure 2 3 DY NI 488 2 Troubleshooting W
95. ialog box then click on the field Optional Change the settings for your interface To view or change GPIB interface information complete the following steps 1 NI 488 2 User Manual for Windows Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer Expand the Devices and Interfaces directory by clicking on the next to the folder Right click on your GPIB interface and select Properties from the drop down menu that appears ni com 4 J Chapter 2 Measurement amp Automation Explorer The GPIB Configuration dialog box appears Figure 2 7 shows the GPIB Configuration dialog box for an AT GPIB TNT Plug and Play interface in Windows NT GPIB Configuration GPIBO AT GPIB TNT Ea GPIB Board y Device Template DEVI a GPIB1 Confi DEV2 GPIB2 m _Cortoue DEV3 ad GPIB3 DEV4 ha Board Type Cancel Help Unload Figure 2 7 GPIB Configuration Utility in Windows NT Select your GPIB Board and click on the Configure button Optional Change the settings for your interface For more information about changing the settings for your interface click on the Help button View GPIB Instrument Information To view information about your GPIB instruments complete the following steps 1 National Instruments Corporation If you have not already done so scan for connected instruments as described in the Scan for GPIB Instru
96. ib 32 dll exports 3 13 to 3 14 Microsoft Visual C C programming instructions 3 12 cable length for high speed data transfers 7 2 to 7 3 NI 488 2 User Manual for Windows l 2 CIC See Controller in Charge CIC CIC Protocol 7 11 CIC status word condition bit position hex value and type table 3 6 description B 4 CMPL status word condition bit position hex value and type table 3 6 description B 3 common questions See troubleshooting and common questions communicating with instruments multiple interfaces or multiple devices 3 5 simple instrument control 3 1 to 3 2 single GPIB device 3 4 to 3 5 using Interactive Control utility 3 7 using Measurement amp Automation Explorer 2 6 to 2 8 advanced communication 2 7 to 2 8 basic communication 2 6 to 2 7 using NI 488 2 Communicator 3 1 to 3 2 communication errors 4 5 repeat addressing 4 5 termination method 4 5 configuration 1 1 to 1 3 See also Interactive Control utility controlling more than one interface 1 2 linear and star system configuration figure 1 1 requirements 1 2 to 1 3 system configuration effects on HS488 7 3 configuration errors 4 3 Configure CFGn message 7 3 Configure Enable CFE message 7 3 Controller in Charge CIC active or inactive A 1 making GPIB board CIC 3 10 7 11 System Controller as CIC A 1 ni com Controllers definition A 1 monitoring by Talker Listener applications 7 11 to 7 12 System Controller A
97. ibrsp until RQS is cleared Stuck SRQ State If autopolling is enabled and the GPIB interface detects an SRQ the driver serial polls all open devices connected to that interface The serial poll continues until either SRQ unasserts or all the devices have been polled If no device responds positively to the serial poll or if SRQ remains in effect because of a faulty instrument or cable a stuck SRQ state is in effect If this happens during an ibwait for RQS the driver reports the ESRQ error If the stuck SRQ state happens no further polls are attempted until an ibwait for RQS is made When ibwait is issued the stuck SRQ state is terminated and the driver attempts a new set of serial polls National Instruments Corporation 7 13 NI 488 2 User Manual for Windows Chapter 7 NI 488 2 Programming Techniques Autopolling and Interrupts If autopolling and interrupts are both enabled the NI 488 2 software can perform autopolling after any device level NI 488 2 call provided that no GPIB I O is currently in progress In this case an automatic serial poll can occur even when your application is not making any calls to the NI 488 2 software Autopolling can also occur when a device level ibwait for RQS is in progress Autopolling is not allowed when an application calls a board level traditional or multi device NI 488 2 call or the stuck SRQ ESRQ condition occurs Windows Me 98 95 In Windows Me 98 95 you can use your GPIB interface wit
98. ick on your GPIB ENET 100 interface and select Device Configuration from the drop down menu that appears For more information about the NI Ethernet Device Configuration utility refer to the Getting Started with Your GPIB ENET 100 and NI 488 2 for Windows Me 98 95 manual NI 488 2 User Manual for Windows 2 16 ni com Chapter 2 Measurement amp Automation Explorer Update GPIB ENET 100 Firmware You can run the Firmware Update utility in Measurement amp Automation Explorer as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB ENET 100 interface and select Update Firmware from the drop down menu that appears For more information about the Firmware Update utility refer to the Getting Started with Your GPIB ENET 100 and NI 488 2 for Windows Me 98 95 manual National Instruments Corporation 2 17 NI 488 2 User Manual for Windows Developing Your NI 488 2 Application This chapter describes how to develop an NI 488 2 application using the NI 488 2 API Simple Instrument Control To establish basic communication with your instrument use the NI 488 2 Communicator as follows 1 National Instruments Corporation If you have not already done so scan for connected instruments as described in the Scan for GPIB Instrume
99. ied mask bit condition occurs TIMO is cleared in all other circumstances END dev brd END indicates either that the GPIB EOI line has been asserted or that the EOS byte has been received if the software is configured to terminate a read on an EOS byte If the GPIB interface is performing a shadow handshake as a result of the ibgts function any other function can return a status word with the END bit set if the END condition occurs before or during that call END is cleared when any I O operation is initiated Some applications might need to know the exact I O read termination mode of a read operation EOI by itself the EOS character by itself or EOI plus the EOS character You can use the ibconfig function option IbcEndBitIsNorma1 to enable a mode in which the END bit is set only when EOI is asserted In this mode if the I O operation completes because of the EOS character by itself END is not set The application should check the last byte of the received buffer to see if it is the EOS character NI 488 2 User Manual for Windows B 2 ni com SRQI brd Appendix B Status Word Conditions RQS dev SRQI indicates that a GPIB device is requesting service SRQI is set whenever the GPIB interface is CIC the GPIB SRQ line is asserted and the automatic serial poll capability is disabled SRQI is cleared either when the GPIB interface ceases to be the CIC or when the GPIB SRQ line is unasserted RQS appears in the
100. in About This Manual EDVR Error Condition with ibentl set to 0xE1030043 519897021 This error occurs if you have enabled DOS NI 488 2 support and attempted to run an existing NI 488 2 DOS application that was compiled with an older unsupported DOS language interface Nl 488 2 User Manual for Windows D 2 ni com Appendix D Windows Me 98 95 Troubleshooting and Common Questions Troubleshooting Device Manager Problems If you are having trouble with your GPIB interface use the Windows Device Manager to troubleshoot your problems To do so complete the following steps 1 Select Start Settings Control Panel 2 Double click on the System icon 3 Select the Device Manager tab and click on the View devices by type button 4 Check to see if the interface listing in the Device Manager appears with an exclamation point or X by it If it does click on the interface listing and then click on the Properties button to display the General property tab for the interface 5 Inthe Device Status section look for the status description and status code number Use the status code descriptions and numbers in Table D 1 to troubleshoot your problem Table D 1 Device Manager Status Codes Code Problem Solution 9 Windows had a problem reading Contact National Instruments to upgrade information from the GPIB interface your GPIB interface This problem can occur if you are using an older revision of the AT GPIB TNT or AT GPIB TNT
101. indicates the number of meters of cable in your system It is called the Configure CFGn message Because HS488 can operate only with cable lengths of 1 to 15 m only CFGn values of 1 through 15 hex 61 through 6F are valid If the cable length was configured properly in the NI 488 2 Configuration utility you can determine how many meters of cable are in your system by calling ibask option IbaHSCableLength in your application For more information about CFE and CFGn messages refer to the Multiline Interface Messages topic in the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual System Configuration Effects on HS488 Maximum HS488 data transfer rates can be limited by your host computer and GPIB system setup For example when using a PC compatible computer with PCI bus the maximum obtainable transfer rate is 8 Mbytes s but when using a PC compatible computer with ISA bus the maximum transfer rate obtainable is only 2 Mbytes s The same IEEE 488 cabling constraints for a 350 ns T1 delay apply to HS488 As you increase the amount of cable in your GPIB configuration the maximum data transfer rate using HS488 decreases For example two HS488 devices connected by two meters of cable can transfer data faster than four HS488 devices connected by 4 m of cable National Instruments Corporation 7 3 NI 488 2 User Manual for Windows Chapter 7 NI 488 2
102. it mask of GPIB events GpibNotifyCallback t Callback callback function void RefData user defined reference data Both board level and device level ibnotify calls are supported by the NI 488 2 driver If you are using device level calls you call ibnotify with a device handle for ud and a mask of RQS CMPL END or TIMO If you are using board level calls you call ibnot ify with a board handle for ud and a mask of any values except RQS or ERR The ibnotify mask bits are identical to the ibwait mask bits In the example of waiting for NI 488 2 User Manual for Windows 7 4 ni com Chapter 7 NI 488 2 Programming Techniques your GPIB device to request service you might choose to pass ibnotify a mask with RQS for device level or SRQI for board level The callback function that you register with the ibnotify call is invoked by the NI 488 2 driver when one or more of the mask bits passed to ibnotify is TRUE The function prototype of the callback is as follows int _ stdcall Callback int ud unit descriptor int ibsta ibsta value int iberr iberr value long ibentl ibcntl value void RefData user defined reference data The callback function is passed a unit descriptor the current values of the NI 488 2 global variables and the user defined reference data that was passed to the original ibnotify call The NI 488 2 driver interprets the return value for the callback as a mask value that is used to automatically
103. ith meaningless bits set in the high byte of the second parameter e ibpad or ibsad called with invalid addresses e ibppc called with invalid parallel poll configurations e A board level traditional NI 488 2 call made with a valid device descriptor or a device level traditional NI 488 2 call made with a board descriptor e A multi device NI 488 2 call made with an invalid address e PPol1Config called with an invalid data line or sense bit Possible solutions for this error are as follows e Make sure that the parameters passed to the NI 488 2 call are valid e Do not use a device descriptor in a board function or vice versa NI 488 2 User Manual for Windows C 4 ni com ESAC 5 Appendix C Error Codes and Solutions Solutions EABO 6 Solutions ENEB 7 ESAC results when ibsic ibsre SendIFC or EnableRemote is called when the GPIB interface does not have System Controller capability Give the GPIB interface System Controller capability by calling ibrsc 1 or by using the NI 488 2 Configuration utility to configure that capability into the software EABO indicates that an I O operation has been canceled usually due to a timeout condition Other causes are calling ibstop or receiving the Device Clear message from the CIC while performing an I O operation Frequently the I O is not progressing the Listener is not continuing to handshake or the Talker has stopped talking or the byte count in the call which
104. izard v NI 488 2 Software Presence Verified v GPIB Hardware Presence Verified v Sequentially Verify GPIB Interfaces GPIB Name Interface Type AT GPIB TNT Plug and Play passed Interface is Not Listed Help Retest Figure 2 3 NI 488 2 Troubleshooting Wizard To view online help for the Troubleshooting Wizard click on the Help button Add a New GPIB Interface To add a new GPIB interface to your system complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Right click on the Devices and Interfaces folder and select Create New 3 Inthe Create New dialog window select the GPIB Interface item and click Finish If you are using Windows 2000 Me 98 95 the Add GPIB Hardware Wizard appears If you are using Windows NT the NI 488 2 Configuration utility appears Nl 488 2 User Manual for Windows 2 4 ni com Chapter 2 Measurement amp Automation Explorer 4 Use either the Add GPIB Hardware Wizard or the NI 488 2 Configuration utility to add your interface Delete a GPIB Interface Before you physically remove a GPIB interface from your system you must remove the hardware information as follows 3 Note If your interface is a PCMCIA GPIB click on the PC Card icon on the taskbar to stop the PC Card When you stop the PC Card the system removes the hardware information from the Device Mana
105. leared whenever the GPIB interface detects the Untalk UNT command its own listen address a talk address other than its own talk address or Interface Clear IFC NI 488 2 User Manual for Windows B 4 ni com Appendix B Status Word Conditions LACS brd LACS indicates whether the GPIB interface is addressed as a Listener LACS is set whenever the GPIB interface detects that its listen address and secondary address if enabled has been sent either by the GPIB interface itself or by another Controller LACS is also set whenever the GPIB interface shadow handshakes as a result of the ibgts function LACS is cleared whenever the GPIB interface detects the Unlisten UNL command its own talk address Interface Clear IFC or that the ibgts function has been called without shadow handshake DTAS brd DTAS indicates whether the GPIB interface has detected a device trigger command DTAS is set whenever the GPIB interface as a Listener detects that the Group Execute Trigger GET command has been sent by another Controller DTAS is cleared on any call immediately following an ibwait call if the DTAS bit is set in the ibwait mask parameter DCAS brd DCAS indicates whether the GPIB interface has detected a device clear command DCAS is set whenever the GPIB interface detects that the Device Clear DCL command has been sent by another Controller or whenever the GPIB interface as a Listener detects that the Selected Device Cl
106. lity 6 9 filename execute indirect file function Interactive Control utility 6 10 turn ON display function Interactive Control utility 6 10 turn OFF display function Interactive Control utility 6 9 A active Controller A 1 addresses See GPIB addresses AllSpoll routine 7 15 7 16 application development See also debugging NI 488 2 programming techniques accessing NI 488 2 driver 3 3 checking status with global variables 3 5 to 3 7 count variables ibcnt and ibcntl 3 7 error variable iberr 3 7 status word ibsta 3 5 to 3 7 choosing programming methodology accessing NI 488 2 driver 3 3 communicating with single GPIB device 3 4 to 3 5 direct entry access 3 3 multiple interfaces and or multiple devices 3 5 NI 488 2 language interfaces 3 3 selecting NI 488 2 API subset 3 4 to 3 5 communicating with instruments multiple interfaces or multiple devices 3 5 single GPIB device 3 4 to 3 5 National Instruments Corporation using Interactive Control utility 3 7 using NI 488 2 Communicator 3 1 to 3 2 interactive instrument control 3 2 to 3 3 language specific instructions 3 12 to 3 16 Borland C C 3 12 direct entry with C 3 13 to 3 16 directly accessing gpib 32 dll exports 3 14 to 3 16 gpib 32 dll exports 3 13 to 3 14 Microsoft Visual Basic 3 13 Microsoft Visual C C 3 12 programming models multiple interfaces or multiple GPIB devices 3 10 to 3 12 single GPIB device 3 8 to 3
107. lutions Check the validity of the call or make sure your GPIB interface and the driver both have the needed capability EFSO 12 EFSO results when an ibrdf or ibwrtf call encounters a problem performing a file operation Specifically this error indicates that the function is unable to open create seek write or close the file being accessed The specific operating system error code for this condition is contained in ibent1 Solutions Possible solutions for this error are as follows e Make sure the filename path and drive that you specified are correct e Make sure that the access mode of the file is correct e Make sure there is enough room on the disk to hold the file National Instruments Corporation C 7 NI 488 2 User Manual for Windows Appendix C Error Codes and Solutions EBUS 14 EBUS results when certain GPIB bus errors occur during device functions All device functions send command bytes to perform addressing and other bus management Devices are expected to accept these command bytes within the time limit specified by the default configuration or the ibtmo function EBUS results if a timeout occurred while sending these command bytes Solutions Possible solutions for this error are as follows e Verify that the instrument is operating correctly e Check for loose or faulty cabling or several powered off instruments on the GPIB e Ifthe timeout period is too short for the driver to send command by
108. ments section earlier in this chapter Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer Expand the Devices and Interfaces directory by clicking on the next to the folder Select your GPIB interface Measurement amp Automation Explorer displays the connected instruments in the right window pane Double click on the instrument displayed in the right window pane Measurement amp Automation Explorer lists all the attributes for the instrument such as the primary address the secondary address if applicable the instrument s response to the identification query IDN and the GPIB interface number to which the device is connected 2 11 NI 488 2 User Manual for Windows Chapter 2 Measurement amp Automation Explorer Change GPIB Device Templates For older NI 488 2 applications you might need to modify one of the device templates to find a given GPIB instrument by name for example ibfind fluke45 Older applications still use ibfind instead of the preferred ibdev to obtain a device handle In new applications avoid using ibfind to obtain device handles and use ibdev instead You can use ibdev to dynamically configure your GPIB device handle ibdev also eliminates unneccessary device name requirements If you must modify a device template refer to one of the following sections Windows Me 98 95 To reconfigure GPIB device templates in Windows Me
109. meter 5500000 Z 6 iste a Pte St Another GPIB L_ Printer Figure 1 2 Example of Multiboard System Configuration Configuration Requirements To achieve the high data transfer rate that the GPIB was designed for you must limit the number of devices on the bus and the physical distance between devices The following restrictions are typical e A maximum separation of 4 m between any two devices and an average separation of 2 m over the entire bus e A maximum total cable length of 20 m e A maximum of 15 devices connected to each bus with at least two thirds powered on NI 488 2 User Manual for Windows 1 2 ni com Chapter 1 Introduction For high speed operation the following restrictions apply e All devices in the system must be powered on e Cable lengths must be as short as possible with up to a maximum of 15 m of cable for each system e There must be at least one equivalent device load per meter of cable If you want to exceed these limitations you can use a bus extender to increase the cable length or a bus expander to increase the number of device loads You can order bus extenders and expanders from National Instruments National Instruments Corporation 1 3 NI 488 2 User Manual for Windows Measurement amp Automation Explorer This chapter describes Measurement amp Automation Explorer an interactive utility you can use with the NI 488 2 software To start M
110. mple C C code that performs a simple query of a GPIB instrument click on the Show Sample button National Instruments Corporation 2 7 NI 488 2 User Manual for Windows Chapter 2 Measurement amp Automation Explorer Advanced Communication For advanced interactive communication with GPIB instruments use the Interactive Control utility as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer Expand the Devices and Interfaces directory by clicking on the next to the folder Right click on your GPIB interface and select Interactive Control from the drop down menu that appears At the command prompt type NI 488 2 API calls to communicate interactively with the your instrument For example you might use ibdev ibclr ibwrt ibrd and ibonl To view the online help for Interactive Control type he 1p at the Interactive Control command prompt View NI 488 2 Software Version To view the NI 488 2 software version complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer Expand the Software directory by clicking on the next to the folder Click on NI 488 2 Software Measurement amp Automation Explorer displays the version number of the NI 488 2 software in the right window pane Monitor Record and Display NI 488 2 Calls To monitor NI 4
111. mple written in C devquery c and the source code for the example written to use direct entry to access gpib 32 d11 dlldevquery c The NI 488 2 software also includes a sample program written in Visual Basic devquery frm Initialization Step 1 Open a Device Use ibdev to open a device handle The ibdev function requires the following parameters e Connect board index typically 0 for GPIBO NI 488 2 User Manual for Windows 3 8 ni com Chapter 3 Developing Your NI 488 2 Application e Primary address for the GPIB instrument refer to the instrument user manual or use the FindLstn function to dynamically determine the GPIB address of your GPIB device as described in Step 2 Determine the GPIB Address of Your Device in the section Applications That Use Multiple Interfaces or Communicate with Multiple GPIB Devices later in this chapter e Secondary address for the GPIB instrument 0 if the GPIB instrument does not use secondary addressing e Timeout period typically set to T10s which is 10 seconds e End of transfer mode typically set to 1 so that EOI is asserted with the last byte of writes e EOS detection mode typically 0 if the GPIB instrument does not use EOS characters A successful ibdev call returns a device handle ud that is used for all device level traditional NI 488 2 calls that communicate with the GPIB instrument Step 2 Clear the Device Use ibcir to clear the device This resets the device s i
112. ms National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB interface and select NI Spy from the drop down menu that appears 4 On the NI Spy toolbar click on the blue arrow button to start a capture Start the NI 488 2 application that you want to monitor National Instruments Corporation 5 1 NI 488 2 User Manual for Windows Chapter 5 NI Spy Utility NI Spy records and displays all NI 488 2 calls as shown in Figure 5 1 HI Spy capture on Iof x File Edit View Spy Help Number GPIB Calls ibsta iberr ibentl Time 1 ibdev 0 3 0 0x0 T10s 13 1 Ox0000 ox0100 0 0x0000 12 53 05 496 2 ibelr UDO 0x0100 0 0x0000 12 53 07 378 3 ibwrt UDO idn 5 0x5 0x0100 0 0x0005 12 53 15 410 4 ibra UDO National Inst 51 0x33 0x2100 0 0x0033 12 53 18 925 5 ibwert UDO conf de max 11 0xB 0x0100 0 Ox000b 1233 6 ibwrt UDO meas de 8 0x8 0x0100 0 0x0008 12 53 52 924 7 ibra UDO 0 9453E2 9 0x9 0x2100 0 0x0009 12 53 56 158 gt For Help press F1 Captured 7 Displayed 7 7 Figure 5 1 NI 488 2 Calls Recorded by NI Spy Using the NI Spy Online Help To view the built in context sensitive online help for the NI Spy utility select Help Help Topics in NI Spy You can also view the online help by clicking on the question
113. multi device calls 7 19 traditional device level calls 7 17 to 7 18 NI 488 2 User Manual for Windows Index SRQ and serial polling device level traditional calls 7 14 to 7 15 examples 7 16 to 7 17 multi device calls 7 15 NI 488 2 Communicator 3 1 NI 488 2 DLL choosing access method 3 3 direct entry access 3 3 NI 488 2 language interfaces 3 3 NI 488 2 DOS support See DOS NI 488 2 applications NI 488 2 programming techniques See also application development asynchronous event notification in Win32 applications 7 4 to 7 9 calling ibnotify function 7 4 to 7 5 ibnotify programming example 7 5 to 7 9 device level calls and bus management 7 11 high speed data transfers 7 2 to 7 3 enabling HS488 7 2 to 7 3 system configuration effects 7 3 parallel polling 7 17 to 7 19 implementing 7 17 to 7 18 multi device NI 488 2 calls 7 19 traditional NI 488 2 calls 7 17 to 7 18 serial polling 7 12 to 7 17 automatic serial polling 7 13 to 7 14 autopolling and interrupts 7 14 stuck SRQ state 7 13 service requests from IEEE 488 devices 7 12 from IEEE 488 2 devices 7 12 SRQ and serial polling with device level traditional NI 488 2 calls 7 14 to 7 15 with multi device NI 488 2 calls 7 15 to 7 17 NI 488 2 User Manual for Windows l 8 Talker Listener applications 7 11 to 7 12 termination of data transfers 7 1 to 7 2 waiting for GPIB conditions 7 4 writing multithread Win32 GPIB applications 7 9 to 7 10
114. nd select Options from the last dialog box This icon denotes a note which alerts you to important information 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 488 2 refer to the ANSI IEEE Standard 488 1 1987 and the ANSI TEEE 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 Bold text in this font denotes the messages and responses that the computer automatically prints to the screen This font also emphasizes lines of code that are different from the other examples Italic text in this font denotes text that is a placeholder for a word or value that you must supply ni com About This Manual Related Documentation The following documents contain information that you may find helpful as you read this manual e ANSI TEEFE Standard 488 1 1987 IEEE Standard
115. ng These global status variables are the status word ibsta the error variable iberr and the count variables ibent and ibcnt1 They contain useful information about the performance of your application Your application should check these variables after each NI 488 2 call The following sections describe each of these global variables and how you can use them in your application 3 Note If your application is a multithreaded application refer to the section Writing Multithreaded Win32 NI 488 2 Applications in Chapter 7 NI 488 2 Programming Techniques Status Word ibsta All NI 488 2 calls update a global status word ibsta which contains information about the state of the GPIB and the GPIB hardware The value stored in ibsta is the return value of all the traditional NI 488 2 calls except ibfind and ibdev You can examine various status bits in ibsta National Instruments Corporation 3 5 NI 488 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application and use that information to make decisions about continued processing If you check for possible errors after each call using the ibsta ERR bit debugging your application is much easier ibsta is a 16 bit value A bit value of one 1 indicates that a certain condition is in effect A bit value of zero 0 indicates that the condition is not in effect Each bit in ibsta can be set for device level traditional NI 488 2 calls dev board level traditional NI
116. nternal functions to the default state Device Communication Step 3 Communicate with the Device Communicate with the device by sending it the IDN query and then reading back the response Many devices respond to this query by returning a description of the device Refer to the documentation that came with your GPIB device to see specific instructions on the proper way to communicate with it Step 3a Use ibwrt to send the IDN query command to the device Step 3b Use ibrd to read the response from the device Continue communicating with the GPIB device until you are finished National Instruments Corporation 3 9 NI 488 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application Cleanup Step 4 Place the Device Offline before Exiting Your Application Use ibon1 to put the device handle offline before you exit the application Applications That Use Multiple Interfaces or Communicate with Multiple GPIB Devices This section describes items you should include in your application and provides general program steps with an NI 488 2 example Items to Include Include the following items in your application e Header files In a C application include the header files windows h and dec1 32 h The standard Windows header file windows h contains definitions used by decl 32 h and decl 32 h contains prototypes for the NI 488 2 calls and constants that you can use in your application e Err
117. nts section in Chapter 2 Measurement amp Automation Explorer Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer Expand the Devices and Interfaces directory by clicking on the next to the folder Select your GPIB interface Measurement amp Automation Explorer displays the connected instruments in the right window pane Right click on your GPIB instrument and select Communicate with Instrument from the drop down menu that appears 3 1 NI 488 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application The NI 488 2 Communicator dialog box appears as shown in Figure 3 1 yr NI 488 2 Communicator GPIBO Instrument 0 Primary Address 1 ji Globals Send String ibsta 0x100 Query Write Read iber None Configured ibentl 4 String Received Show Sample Exit Figure 3 1 NI 488 2 Communicator 6 Type a command in the Send String field and do one of the following e To write a command to the instrument then read a response back click on the Query button To write a command to the instrument click on the Write button To read a response from the instrument click on the Read button To view sample C C code that performs a simple query of a GPIB instrument click on the Show Sample button Interactive Instrument Control Before you write your NI 488 2 application you might w
118. oller In Charge Only the CIC is able to send command bytes to the devices on the bus to perform device addressing or other bus management activities Use one of the following methods to make your GPIB interface the CIC e Ifyour GPIB interface is configured as the System Controller default it automatically makes itself the CIC by asserting the IFC line the first time you make a device level call e If your setup includes more than one Controller or if your GPIB interface is not configured as the System Controller use the CIC Protocol method To use the protocol issue the ibconfig function option IbcCICPROT or use the NI 488 2 Configuration utility to activate the CIC protocol If the interface is not CIC and you make a device level call with the CIC protocol enabled the following sequence occurs 1 The GPIB interface asserts the SRQ line 2 The current CIC serial polls the interface 3 The interface returns a response byte of hex 42 4 The current CIC passes control to the GPIB interface If the current CIC does not pass control the NI 488 2 driver returns the ECIC error code to your application This error can occur if the current CIC does not understand the CIC protocol If this happens you could send a device specific command requesting control for the GPIB interface Then use a board level ibwait command to wait for CIC Talker Listener Applications Although designed for Controller In Charge applications you
119. om participating in polls Low speed data transfer between the GPIB interface and memory in which the CPU moves each data byte according to program instructions See DMA The GPIB software and the user application must resynchronize after asynchronous I O operations have completed Request Service NI 488 2 User Manual for Windows G 6 ni com SDC semaphore serial poll service request source handshake SPD SPE SRQ status byte status word synchronous System Controller National Instruments Corporation G 7 Glossary Seconds Selected Device Clear The GPIB command used to reset internal or device functions of an addressed Listener See DCL An object that maintains a count between zero and some maximum value limiting the number of threads that are simultaneously accessing a shared resource The process of polling and reading the status byte of one device at a time See parallel poll See SRQ The GPIB interface function that transmits data and commands Talkers use this function to send data and the Controller uses it to send commands See acceptor handshake and handshake Serial Poll Disable The GPIB command used to cancel an SPE command Serial Poll Enable The GPIB command used to enable a specific device to be polled That device must also be addressed to talk See SPD Service Request The GPIB line that a device asserts to notify the CIC that the device needs servicing The IEE
120. ommunicate its status whenever possible Although this method is not possible with many devices it is usually the best option Your delays are controlled by the device and your application can adjust itself and work independently on any platform Other delay mechanisms probably exhibit differing behaviors on different platforms and thus might not eliminate timing errors NI 488 2 User Manual for Windows 4 4 ni com Chapter 4 Debugging Your Application Communication Errors The following sections describe communication errors you might encounter in your application Repeat Addressing Devices adhering to the IEEE 488 2 standard should remain in their current state until specific commands are sent across the GPIB to change their state However some devices require GPIB addressing before any GPIB activity Therefore you might need to configure your NI 488 2 driver to perform repeat addressing if your device does not remain in its currently addressed state You can either reconfigure from your application using ibconfig or reconfigure using the NI 488 2 Configuration utility 3 Note National Instruments recommends using ibconfig to modify the configuration If your application uses ibconfig it works properly regardless of the previous configuration For more information about ibconfig refer to the description of ibconfig in the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Document
121. onal Instruments NI 488 2 Explore GPIB and expand the Devices and Interfaces directory by clicking on the next to the folder Measurement amp Automation Explorer lists your installed GPIB hardware under Devices and Interfaces How many GPIB interfaces can I configure for use with the NI 488 2 software You can configure the NI 488 2 software to communicate with up to 100 GPIB interfaces How many devices can I configure for use with the NI 488 2 software You can configure the NI 488 2 software to use up to 1 024 logical devices The default number of devices is 32 The maximum number of physical devices you should connect to a single GPIB interface is 14 or fewer depending on your system configuration NI 488 2 User Manual for Windows D 6 ni com Appendix D Windows Me 98 95 Troubleshooting and Common Questions Are interrupts and DMA required for the NI 488 2 software Neither interrupts nor DMA are required However if you are using a GPIB interface with Analyzer capability PCMCIA GPIB or AT GPIB TNT at least one interrupt level is required for the GPIB Analyzer driver In Windows Me 98 95 you can use your GPIB interface without interrupts but the NI 488 2 software performance is significantly slower without interrupts For example transfer sizes between and 10 bytes transfer at a rate of only 2 of the transfer rate with enabled interrupts As the transfer size increases the performance degradation decreases sli
122. onditions REM brd CIC brd REM indicates whether the interface is in the remote state REM is set whenever the Remote Enable REN GPIB line is asserted and the GPIB interface detects that its listen address has been sent either by the GPIB interface or by another Controller REM is cleared in the following situations e When REN becomes unasserted e When the GPIB interface as a Listener detects that the Go to Local GTL command has been sent either by the GPIB interface or by another Controller e When the ibloc function is called while the LOK bit is cleared in the status word ATN brd CIC indicates whether the GPIB interface is the Controller In Charge CIC is set when the SendIFC or ibsic call is executed either while the GPIB interface is System Controller or when another Controller passes control to the GPIB interface CIC is cleared either when the GPIB interface detects Interface Clear IFC from the System Controller or when the GPIB interface passes control to another device TACS brd ATN indicates the state of the GPIB Attention ATN line ATN is set whenever the GPIB ATN line is asserted and it is cleared when the ATN line is unasserted TACS indicates whether the GPIB interface is addressed as a Talker TACS is set whenever the GPIB interface detects that its talk address and secondary address if enabled has been sent either by the GPIB interface itself or by another Controller TACS is c
123. or MAV are set or when a manufacturer defined condition occurs NI 488 2 User Manual for Windows 7 12 ni com Chapter 7 NI 488 2 Programming Techniques Automatic Serial Polling You can enable automatic serial polling if you want your application to conduct a serial poll automatically when the SRQ line is asserted The autopolling procedure occurs as follows 1 To enable autopolling use the configuration function ibconfig with option LbcAUTOPOLL or the NI 488 2 Configuration utility Autopolling is enabled by default 2 When the SRQ line is asserted the driver automatically serial polls the open devices 3 Each positive serial poll response bit 6 or hex 40 is set is stored in a queue associated with the device that sent it The RQS bit of the device status word ibsta is set 4 The polling continues until SRQ is unasserted or an error condition is detected 5 To empty the queue use the ibrsp function ibrsp returns the first queued response Other responses are read in first in first out FIFO fashion If the RQS bit of the status word is not set when ibrsp is called a serial poll is conducted and returns the response received Empty the queue as soon as an automatic serial poll occurs because responses might be discarded if the queue is full 6 If the RQS bit of the status word is still set after ibrsp is called the response byte queue contains at least one more response byte If this happens continue to call
124. or checking Check for errors after each NI 488 2 call e Error handling Declare and define a function to handle NI 488 2 errors This function takes the device offline and closes the application If the function is declared as void gpiberr char msg function prototype Then your application invokes it as follows if ibsta amp ERR gpiberr NI 488 2 error General Program Steps and Examples The following steps show you how to use the multi device NI 488 2 calls in your application The NI 488 2 software includes the source code for an example written in C 4882query c and the source code for the example written to use direct entry to access the gpib 32 d11 d114882query c The NI 488 2 software also includes a sample program written in Visual Basic query4882 frm NI 488 2 User Manual for Windows 3 10 ni com Chapter 3 Developing Your NI 488 2 Application Initialization Step 1 Become Controller In Charge CIC Use SendIFC to initialize the bus and the GPIB interface so that the GPIB interface is Controller In Charge CIC The only argument of SendIFC is the GPIB interface number typically 0 for GPIBo Step 2 Determine the GPIB Address of Your Device Use FindLstn to find all the devices attached to the GPIB The FindLstn function requires the following parameters e Interface number typically 0 for GPIBO e A list of primary addresses terminated with the NOADDR constant e A list for rep
125. or this error are as follows e You can correct the EDMA problem in the hardware by using the Device Manager in Windows Me 98 95 or the NI 488 2 Configuration utility in Windows 2000 NT to reconfigure the hardware to not use a DMA resource e You can correct the EDMA problem in the software by using ibdma to disable DMA Solutions EOIP occurs when an asynchronous I O operation has not finished before some other call is made During asynchronous I O you can only use ibstop ibnotify ibwait and ibon1 or perform other non GPIB operations If any other call is attempted EOIP is returned Resynchronize the driver and the application before making any further NI 488 2 calls Resynchronization is accomplished by using one of the following functions ibnotify If the ibsta value passed to the ibnotify callback contains CMPL the driver and application are resynchronized NI 488 2 User Manual for Windows C 6 ni com Appendix C Error Codes and Solutions ibwait If the returned ibsta contains CMPL the driver and application are resynchronized ibstop The I O is canceled the driver and application are resynchronized ibonl The I O is canceled and the interface is reset the driver and application are resynchronized ECAP 11 ECAP results when your GPIB interface lacks the ability to carry out an operation or when a particular capability has been disabled in the software and a call is made that requires the capability So
126. orted GPIB addresses of devices found listening on the GPIB e Limit which is the number of the GPIB addresses to report Use FindLstn to test for the presence of all of the primary addresses that are passed to it If a device is present at a particular primary address then the primary address is stored in the GPIB addresses list Otherwise all secondary addresses of the given primary address are tested and the GPIB address of any devices found are stored in the GPIB addresses list When you have the list of GPIB addresses you can determine which one corresponds to your instrument and use it for subsequent calls Alternately if you already know your GPIB device s primary and secondary address you can create an appropriate GPIB address to use in subsequent NI 488 2 calls as follows a GPIB address is a 16 bit value that contains the primary address in the low byte and the secondary address in the high byte If you are not using secondary addressing the secondary address is 0 For example if the primary address is 1 then the 16 bit value is 0x01 otherwise if the primary address is 1 and the secondary address is 0x67 then the 16 bit value is 0x6701 Step 3 Initialize the Devices Use DevClearList to clear the devices on the GPIB The first argument is the GPIB interface number The second argument is the list of GPIB addresses that were found to be listening as determined in Step 2 National Instruments Corporation 3 11 NI 488
127. owing on the command line cl cprog c gpib 32 obj NI 488 2 User Manual for Windows 3 12 ni com Chapter 3 Developing Your NI 488 2 Application Borland C C Version 4 0 or Later Before you compile your Win32 C application make sure that the following lines are included at the beginning of your program include lt windows h gt include decl 32 h To compile and link a Win32 console application named cprog in a DOS shell type the following on the command line bec32 w32 cprog c borlandc_gpib 32 obj Visual Basic Version 4 0 or Later With Visual Basic you can access the traditional NI 488 2 calls as subroutines using the BASIC keyword CALL followed by the traditional NI 488 2 call name or you can access them using the i1 set of functions With some of the NI 488 2 calls for example ibrd and Receive the length of the string buffer is automatically calculated within the actual function or subroutine which eliminates the need to pass in the length as an extra parameter For more information about function syntax for Visual Basic refer to the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual Before you run your Visual Basic application include the niglobal bas and vbib 32 bas files in your application project file Direct Entry with C The following sections describe how to use direct entry with C gpib 32 dll Exports
128. ple devices use the multi device NI 488 2 calls Whichever option you choose bus management operations necessary for device communication are performed automatically The following sections describe some differences between the traditional NI 488 2 calls and the multi device NI 488 2 calls Communicating with a Single GPIB Device If your system has only one device attached to each interface the traditional NI 488 2 calls are probably sufficient for your programming needs A typical NI 488 2 application with a single device has three phases e Initialization use ibdev to get a handle and use ibclr to clear the device e Device Communication use ibwrt ibrd ibtrg ibrsp and ibwait to communicate with the device e Cleanup use ibon1 to put the handle offline Refer to the sample applications that are installed with the NI 488 2 software to see detailed examples for different GPIB device types For NI 488 2 applications that need to control the GPIB in non typical ways for example to communicate with non compliant GPIB devices there are a set of low level functions that perform rudimentary GPIB applications If you use these functions you need to understand GPIB management details like how to address talkers and listeners Refer to Appendix A GPIB Basics for some details on GPIB management The set of low level functions are called board level functions They access the interface directly and require you to handle the addres
129. r eotmode Send data bytes SendIFC Send interface clear SendList addrlist buffer eotmode Send data to multiple devices SendLLO Put devices in local lockout SendSetup addrlist Send setup SetRWLS addrlist Put devices in remote with lockout state TestSRQ Test for service request TestSys addrlist Cause multiple devices to perform self tests A rigger address Trigger a device a TriggerList addrlist Trigger multiple devices WaitSRQ Wait for service request Table 6 4 Auxiliary Functions in Interactive Control Function Description set udname Select active device or interface where udname is the symbolic name of the new device or interface for example dev1 or gpibo Call ibfind or ibdev initially to open each device or interface set 488 2 v Start using multi device NI 488 2 calls for interface v help Display the Interactive Control utility online help help option Display help information about option where option is any NI 488 2 or auxiliary call for example help ibwrt or help set Repeat previous function Turn OFF display National Instruments Corporation 6 9 NI 488 2 User Manual for Windows Chapter 6 Interactive Control Utility Table 6 4 Auxiliary Functions in Interactive Control Continued Function Description Turn ON display n function E
130. r more information about using NI Spy select Help Help Topics in NI Spy or refer to Chapter 5 NJ Spy Utility Global Status Variables At the end of each NI 488 2 call the global status variables ibsta iberr ibent and ibcnt1 are updated If you are developing an NI 488 2 application you should check for errors after each NI 488 2 call If a NI 488 2 call failed the high bit of ibsta the ERR bit is set For a failed NI 488 2 call iberr contains a value that defines the error In some error cases the value in ibcnt1 contains even more error information You can use NI Spy to determine which NI 488 2 call is failing Once you know which NI 488 2 call fails refer to Appendix B Status Word Conditions and Appendix C Error Codes and Solutions for help understanding why the NI 488 2 call failed This information is also available in the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual NI 488 2 User Manual for Windows 4 2 ni com Chapter 4 Debugging Your Application Existing Applications If the application does not have built in error detection handling you can use NI Spy to determine which NI 488 2 call is failing To start NI Spy refer to the MI Spy section earlier in this chapter After you have an NI Spy capture file you can use NI Spy to search for failed NI 488 2 calls by searching for calls with the ERR bit set Once
131. re and the NI 488 2 software use the NI 488 2 Getting Started Wizard To do so select Start Programs National Instruments NI 488 2 Getting Started Wizard How do I troubleshoot problems Run the NI 488 2 Troubleshooting Wizard To do so select Start Programs National Instruments NI 488 2 Explore GPIB Then select Help Troubleshooting NI 488 2 Troubleshooting Wizard National Instruments Corporation D 5 NI 488 2 User Manual for Windows Appendix D Windows Me 98 95 Troubleshooting and Common Questions How can I determine which version of the NI 488 2 software I have installed To view the NI 488 2 software version complete the following steps 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Software directory by clicking on the next to the folder 3 Click on NI 488 2 Software Measurement amp Automation Explorer displays the version number of the NI 488 2 software in the right window pane What do I do if my GPIB hardware is listed in the Windows Device Manager with a circled X or an exclamation point overlaid on it Refer to the Troubleshooting Device Manager Problems section of this appendix for information about what might cause this problem If you already completed the troubleshooting steps contact National Instruments How can I determine which type of GPIB hardware I have installed Select Start Programs Nati
132. riginal Configuration Current checkbox NI 488 2 User Manual for Windows D 4 ni com Appendix D Windows Me 98 95 Troubleshooting and Common Questions 7 Click on the OK button to save your changes On the Device Manager tab the disabled device has a red X overlaid on it The red X indicates that the device is disabled Step 2 Remove Your GPIB Interface from the Device Manager To remove your GPIB interface from the Device Manager complete the following steps 1 On the Device Manager tab double click on the National Instruments GPIB Interfaces item If you are removing a PCMCIA GPIB interface double click on the Multifunction Adapters item 2 Click on the GPIB interface that does not have an interrupt resource and click on the Remove button If you are removing a PCMCIA GPIB interface click on the NI PCMCIA GPIB Multifunction Parent item and click on the Remove button Step 3 Refresh the Device Manager or Reinstall Your GPIB interface On the Device Manager tab click on the Refresh button If your GPIB interface does not appear under National Instruments GPIB Interfaces your GPIB interface is not Plug and Play In this case you must use the Add GPIB Hardware Wizard to reinstall your interface To start the wizard select Start Programs National Instruments NI 488 2 Add GPIB Hardware and follow the instructions on the screen Common Questions How do I get started To get started with your GPIB hardwa
133. rogramming Techniques char SerialPollResponse 0 ibwait DeviceHandle TIMO RQS if ibsta amp ROS printf Device asserted SRQ n Use ibrsp to retrieve the serial poll response ibrsp DeviceHandle amp SerialPollResponse return SerialPollResponse SRQ and Serial Polling with Multi Device NI 488 2 Calls The NI 488 2 software includes a set of multi device NI 488 2 calls that you can use to conduct SRQ servicing and serial polling Calls pertinent to SRQ servicing and serial polling are Al1Spoll1 ReadStatusByte FindRQS Test SRQ and WaitSRQ Following are descriptions of each of the calls e A11Spo11 can serial poll multiple devices with a single call It places the status bytes from each polled instrument into a predefined array Then you must check the RQS bit of each status byte to determine whether that device requested service e ReadStatusByte is similar to Al1Spol11 except that it only serial polls a single device It is also similar to the device level NI 488 2 ibrsp function e FindRQS serial polls a list of devices until it finds a device that is requesting service or until it has polled all of the devices on the list The call returns the index and status byte value of the device requesting service e TestSRQ determines whether the SRQ line is asserted and returns to the program immediately e WaitSRQ is similar to TestSRQ except that WaitSRQ suspends the application until
134. ronization In this case synchronization of access to these globals is not necessary National Instruments Corporation 7 5 NI 488 2 User Manual for Windows Chapter 7 NI 488 2 Programming Techniques because of the way they are used in the application only a single thread is writing the global values and that thread only adds information increases the count or adds another reading to the array of floats int _ stdcall MyCallback int ud int LocalIbsta int LocallIberr long LocalIbcentl void RefData int ReadingsTaken 0 float Readings 1000 BOOL DeviceError FALSE char expectedResponse 0x43 int main int ud Assign a unique identifier to the device and store it in the variable ud ibdev opens an available device and assigns it to access GPIBO with a primary address of 1 a secondary address of 0 a timeout of 10 seconds the END message enabled and the EOS mode disabled If ud is less than zero then print an error message that the call failed and exit the program ud ibdev 0 connect board fle primary address of GPIB device 0 secondary address of GPIB device T10s 10 second I O timeout Ae EOT mode turned on 0 EOS mode disabled if ud lt 0 printf ibdev failed n return 0 Issue a request to the device to send the data If the ERR bit is set in ibsta then print an error message that the call failed and exit the program ibwrt ud
135. rporation 2 15 NI 488 2 User Manual for Windows Chapter 2 Measurement amp Automation Explorer Update GPIB ENET Firmware You can run the Update Firmware utility in Measurement amp Automation Explorer as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB ENET interface and select Update Firmware from the drop down menu that appears To view the built in context sensitive help for the Update Firmware utility click on the Help button View or Change GPIB ENET 100 Network Settings Windows Me 98 95 Only To view or change the network settings of your GPIB ENET 100 refer to the following sections For more information about your GPIB ENET 100 network settings refer to the Getting Started with Your GPIB ENET 100 and NI 488 2 for Windows Me 98 95 manual Device Configuration You can run the NI Ethernet Device Configuration utility in Measurement amp Automation Explorer as follows 1 Contact your network administrator to determine whether you should manually configure the network parameters or enable DHCP 2 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 3 Expand the Devices and Interfaces directory by clicking on the next to the folder 4 Right cl
136. s Me 98 95 manual Assign IP Address You can run the Assign IP Address utility in Measurement amp Automation Explorer as follows 1 Contact your network administrator to determine whether you should use the Assign IP Address utility to assign the IP address manually 2 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 3 Expand the Devices and Interfaces directory by clicking on the next to the folder 4 Right click on your GPIB ENET interface and select Assign IP Address from the drop down menu that appears To view the built in context sensitive help for the Assign IP Address utility click on the Help button Configure Advanced IP Settings You can run the Advanced IP Settings utility in Measurement amp Automation Explorer as follows 1 Contact your network administrator for the proper subnet information including the broadcast IP address and netmask and up to four router IP addresses 2 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 3 Expand the Devices and Interfaces directory by clicking on the next to the folder 4 Right click on your GPIB ENET interface and select Advanced IP Settings from the drop down menu that appears To view the built in context sensitive help for the Advanced IP Settings utility click on the Help button National Instruments Co
137. s 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 Instruments 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
138. ser manual that came with your instrument For information about using the Interactive Control utility and detailed examples refer to Chapter 6 Interactive Control Utility National Instruments Corporation 3 7 NI 488 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application Programming Models Applications That Communicate with a Single GPIB Device This section describes items you should include in your application and provides general program steps with an NI 488 2 example Items to Include Include the following items in your application e Header files In a C application include the header files windows h and decl1 32 h The standard Windows header file windows h contains definitions used by decl 32 h and decl 32 h contains prototypes for the NI 488 2 calls and constants that you can use in your application e Error checking Check for errors after each NI 488 2 call e Error handling Declare and define a function to handle NI 488 2 errors This function takes the device offline and closes the application If the function is declared as void gpiberr char msg function prototype Then your application invokes it as follows if ibsta amp ERR gpiberr NI 488 2 error General Program Steps and Examples The following steps show you how to use the device level traditional NI 488 2 calls in your application The NI 488 2 software includes the source code for an exa
139. sible solutions for this error are as follows National Instruments Corporation Make sure that the GPIB address of your device matches the GPIB address of the device to which you want to write data Use the appropriate hex code in ibcmd to address your device Check your cable connections and make sure at least two thirds of your devices are powered on Call ibpad or ibsad if necessary to match the configured address to the device switch settings C 3 NI 488 2 User Manual for Windows Appendix C Error Codes and Solutions EADR 3 Solutions EARG 4 EADR occurs when the GPIB interface is CIC and is not properly addressing itself before read and write functions This error is usually associated with board level functions EADR is also returned by the function ibgts when the shadow handshake feature is requested and the GPIB ATN line is already unasserted In this case the shadow handshake is not possible and the error is returned to notify you of that fact Possible solutions for this error are as follows e Make sure that the GPIB interface is addressed correctly before calling ibrd ibwrt RcvRespMsg or SendDataBytes e Avoid calling ibgts except immediately after an ibemd call ibcmd causes ATN to be asserted Solutions EARG results when an invalid argument is passed to a function call The following are some examples e ibtmo called with a value not in the range 0 through 17 e ibeos called w
140. sing and bus management protocol These functions give you the flexibility and control to handle situations such as the following e Communicating with non compliant non IEEE 488 2 devices e Altering various low level interface configurations e Managing the bus in non typical ways NI 488 2 User Manual for Windows 3 4 ni com Chapter 3 Developing Your NI 488 2 Application Board level functions that an NI 488 2 application might use include the following ibemd ibrd ibwrt and ibconfig For a detailed list refer to the NI 488 2 online help For instructions on accessing the online help refer to the Using the NI 488 2 Documentation section in About This Manual Using Multiple Interfaces and or Multiple Devices When your system includes an interface that must access multiple devices use the multi device NI 488 2 calls which can perform the following tasks with a single call e Find the Listeners on the bus using FindLstn e Find a device requesting service using FindRQS e Determine the state of the SRQ line or wait for SRQ to be asserted using Test SRQ or WaitSRQ e Address multiple devices to receive a command using SendList You can mix board level traditional NI 488 2 calls with the multi device NI 488 2 calls to have access to all the NI 488 2 functionality Checking Status with Global Variables Each NI 488 2 API call updates four global variables to reflect the status of the device or interface that you are usi
141. sing in Interactive Control utility example 6 2 ibeos function 7 1 ibeot function 7 1 iberr error variable 3 7 ibnotify function asynchronous event notification example 7 5 to 7 9 calling 7 4 to 7 5 NI 488 2 User Manual for Windows Index ibonl function placing device offline 3 9 3 12 using in Interactive Control utility example 6 3 to 6 4 ibppc function 7 17 to 7 18 ibrd function reading response from device 3 9 using in Interactive Control utility example 6 3 ibrpp function 7 18 ibrsp function automatic serial polling 7 13 SRQ and serial polling 7 14 ibsta See status word ibsta ibwait function Talker Listener applications 7 11 terminating stuck SRQ state 7 13 waiting for GPIB conditions 7 4 ibwrt function sending IDN query to device 3 9 using in Interactive Control utility example 6 3 IFC interface clear line A 3 instruments See communicating with instruments GPIB instruments Interactive Control utility auxiliary functions table 6 9 to 6 10 communicating with instruments 3 2 to 3 3 count 6 11 error information 6 10 to 6 11 getting started 6 1 to 6 4 NI 488 function examples 6 2 to 6 4 overview 6 1 programming considerations 3 2 to 3 3 status word 6 10 syntax 6 4 to 6 10 addresses 6 5 board level traditional NI 488 2 calls table 6 7 to 6 8 NI 488 2 User Manual for Windows l 6 device level traditional NI 488 2 calls table 6 5 to 6 6 multi device NI 488 2 c
142. so that bytes can be sent asynchronously for example without a clock at the speed of the slowest device For more information about handshaking refer to the ANSI TEEE Standard 488 1 1987 NI 488 2 User Manual for Windows Glossary hex high level function HS488 ibent ibentl iberr ibsta TEEE interface message T O T O address Hexadecimal a number represented in base 16 For example decimal 16 is hex 10 See device level function A high speed data transfer protocol for IEEE 488 This protocol increases performance for GPIB reads and writes up to 8 Mbytes s depending on your system Hertz After each NI 488 2 I O call this global variable contains the actual number of bytes transmitted On systems with a 16 bit integer such as MS DOS ibcnt is a 16 bit integer and ibcnt1 is a 32 bit integer For cross platform compatibility use ibcnt1 After each NI 488 2 I O call this global variable contains the actual number of bytes transmitted On systems with a 16 bit integer such as MS DOS ibcnt is a 16 bit integer and ibcnt1 is a 32 bit integer For cross platform compatibility use ibcnt1 A global variable that contains the specific error code associated with a function call that failed At the end of each function call this global variable status word contains status information Institute of Electrical and Electronic Engineers A broadcast message sent from the Controller to all devic
143. t notification in Win32 applications Event Status bit ESB 7 12 to 7 13 execute function n times n function Interactive Control utility 6 10 execute indirect file function Interactive Control utility 6 10 execute previous function n times n function Interactive Control utility 6 10 existing applications running DOS NI 488 2 applications Windows Me 98 95 3 17 Windows 2000 NT 3 18 Win32 and Win16 NI 488 2 applications 3 17 F FindLstn function 3 11 FindRQS function 7 15 7 16 G General Purpose Interface Bus See GPIB global variables 3 5 to 3 7 count variables ibcnt and ibcntl 3 7 debugging applications 4 2 error variable iberr 3 7 status word ibsta 3 5 to 3 7 writing multithread Win32 GPIB applications 7 9 to 7 10 GPIB configuration 1 1 to 1 3 See also Interactive Control utility controlling more than one board 1 2 linear and star system configuration figure 1 1 requirements 1 2 to 1 3 ni com definition A 1 overview A 1 sending messages across A 2 to A 3 data lines A 2 handshake lines A 3 interface management lines A 3 Talkers Listeners and Controllers A 1 gpib 32 dll exports accessing directly 3 14 to 3 16 direct entry with C 3 13 to 3 14 GPIB addresses address bit configuration figure A 2 primary and secondary A 2 repeat addressing 4 5 syntax in Interactive Control utility 6 5 GPIB device templates changing Windows Me 98 95 2 12 Windows 2000 NT
144. t environment you can select a method for accessing the driver and based on your NI 488 2 programming needs you can choose how to use the NI 488 2 API Choosing a Method to Access the NI 488 2 Driver Applications can access the NI 488 2 dynamic link library DLL gpib 32 d11 either by using an NI 488 2 language interface or by direct access NI 488 2 Language Interfaces You can use a language interface if your program is written in Microsoft Visual C C 2 0 or later Borland C C 4 0 or later or Microsoft Visual Basic 4 0 or later Otherwise you must access gpib 32 d11 directly Direct Entry Access You can access the DLL directly from any programming environment that allows you to request addresses of variables and functions that a DLL exports gpib 32 d11 exports pointers to each of the global variables and all the NI 488 2 calls National Instruments Corporation 3 3 NI 488 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application Choosing How to Use the NI 488 2 API The NI 488 2 API has two subsets of calls to meet your application needs Both of these sets the traditional calls and the multi device calls are compatible across computer platforms and operating systems so you can port programs to other platforms with little or no source code modification For most applications the traditional NI 488 2 calls are sufficient If you have a complex configuration with one or more interfaces and multi
145. terfaces directory by clicking on the next to the folder 4 Select your GPIB interface and select Tools NI 488 2 DOS Support from the Explorer menu National Instruments Corporation 3 17 NI 488 2 User Manual for Windows Chapter 3 Developing Your NI 488 2 Application 5 Enable or disable DOS support in the NI 488 2 Settings dialog box and click on the OK button 6 If you are prompted to do so restart your system Running Existing DOS NI 488 2 Applications under Windows 2000 NT To run DOS NI 488 2 applications you must enable NI 488 2 DOS support under Windows 2000 NT To enable NI 488 2 DOS support in Windows 2000 NT complete the following steps 1 Open your config nt file located in the Windows 2000 NT system32 directory for example c windows system32 2 Find the following lines REM To run DOS GPIB applications uncomment the REM following line REM device lt path gt doswinl6 gpib nt com where lt paths is the directory in which you installed the NI 488 2 software 3 Remove REM from the last line so that it reads as follows device lt path gt doswinl6 gpib nt com To disable DOS support add REM back to the line where it was removed NI 488 2 User Manual for Windows 3 18 ni com Debugging Your Application This chapter describes several ways to debug your application NI Spy The NI Spy utility monitors NI 488 2 API calls made by NI 488 2 applications It records NI 488 2 A
146. tes increase the timeout period ESTB 15 ESTB is reported only by the ibrsp function ESTB indicates that one or more serial poll status bytes received from automatic serial polls have been discarded because of a lack of storage space Several older status bytes are available however the oldest is being returned by the ibrsp call Solutions Possible solutions for this error are as follows e Call ibrsp more frequently to empty the queue e Disable autopolling with the ibconfig function option IbcAUTOPOLL or the NI 488 2 Configuration utility as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB interface and select Properties from the drop down menu that appears NI 488 2 User Manual for Windows C 8 ni com ESRQ 16 Appendix C Error Codes and Solutions Solutions ETAB 20 ESRQ can only be returned by a device level ibwait call with RQS set in the mask ESRQ indicates that a wait for RQS is not possible because the GPIB SRQ line is stuck on This situation can be caused by the following events e Usually a device unknown to the software is asserting SRQ Because the software does not know of this device it can never serial poll the device and unassert SRQ e A GPIB bus tester or similar equipment might be for
147. th the last byte of writes and the EOS modes are disabled You can use the ibeot function to enable or disable the end of transmission EOT mode If EOT mode is enabled the GPIB EOI line is asserted when the last byte of a write is sent out on the GPIB If it is disabled the EOI line is not asserted with the last byte of a write You can use the ibeos function to enable disable or configure the EOS modes EOS mode configuration includes the following information e A7 bit or 8 bit EOS byte e EOS comparison method This indicates whether the EOS byte has seven or eight significant bits For a 7 bit EOS byte the eighth bit of the EOS byte is ignored e EOS write method TIf this is enabled the GPIB EOI line is automatically asserted when the EOS byte is written to the GPIB If the buffer passed into an ibwrt call contains five occurrences of the EOS byte the EOI line is asserted as each of the five EOS bytes are written to the GPIB If an ibwrt buffer does not contain an occurrence of the EOS byte the EOI line is not asserted unless the EOT mode is enabled in which case the EOI line is asserted with the last byte of the write National Instruments Corporation 7 1 NI 488 2 User Manual for Windows Chapter 7 NI 488 2 Programming Techniques e EOS read method TIf this is enabled ibrd ibrda and ibrdf calls are terminated when the EOS byte is detected on the GPIB when the GPIB EOI line is asserted or when the specified co
148. ty 6 4 to 6 5 stuck SRQ state 7 13 System Controller A 1 system integration by National Instruments F 1 T TACS status word condition bit position hex value and type table 3 6 description B 4 Talker Listener applications 7 12 talk address A 2 Talker Listener applications 7 11 to 7 12 Talkers A 1 technical support resources F 1 termination methods errors caused by 4 5 termination of data transfers 7 1 to 7 2 TestSRQ routine 7 15 timing errors 4 4 TIMO status word condition bit position hex value and type table 3 6 description B 2 troubleshooting and common questions See also debugging NI Spy utility using Measurement amp Automation Explorer 2 4 Windows Me 98 95 D 1 to D 8 common questions D 5 to D 8 Device Manager device status code D 3 EDVR error conditions D 1 to D 2 NI 488 2 User Manual for Windows I 10 enabling interrupts D 4 to D 5 Windows 2000 NT E 1 to E 3 turn OFF display function Interactive Control utility 6 9 turn ON display function Interactive Control utility 6 10 V Visual Basic programming instructions 3 12 W WaitSRQ routine 7 15 Web support from National Instruments F 1 Win32 and Win16 NI 488 2 applications asynchronous event notification 7 4 to 7 9 running 3 17 running existing applications 3 17 writing multithreaded applications 7 9 to 7 10 Windows Me 98 95 autopolling and interrupts 7 14 changing GPIB device templates 2 12 enabling
149. u can use secondary addressing A secondary address is a number in the range hex 60 to hex 7E When you use secondary addressing the Controller sends the primary talk or listen address of the device followed by the secondary address of the device Sending Messages across the GPIB Data Lines Devices on the bus communicate by sending messages Signals and lines transfer these messages across the GPIB interface which consists of 16 signal lines and 8 ground return shield drain lines The 16 signal lines are discussed in the following sections Eight data lines DIO1 through DIO8 carry both data and command messages NI 488 2 User Manual for Windows A 2 ni com Handshake Lines Appendix A GPIB Basics Three hardware handshake lines asynchronously control the transfer of message bytes between devices This process is a three wire interlocked handshake and it guarantees that devices send and receive message bytes on the data lines without transmission error Table A 1 summarizes the GPIB handshake lines Table A 1 GPIB Handshake Lines Line Description NRFD not ready for data Listening device is ready not ready to receive a message byte Also used by the Talker to signal high speed GPIB transfers NDAC not data accepted Listening device has has not accepted a message byte DAV data valid Talking device indicates signals on data lines are stable valid data Interface Man
150. ubleshooting the error condition EDVR Error Condition with ibcntl Set to OxE028002C 534249428 If a call is made with an interface number that is within the range of allowed interface numbers typically 0 to 3 but which has not been assigned to a GPIB interface an EDVR error condition occurs with ibcnt1 set to OxE028002C You can assign an interface number to a GPIB interface by configuring the NI 488 2 software and selecting an interface name For information about how to configure the NI 488 2 software refer to the online help in the NI 488 2 Configuration utility as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB to start Measurement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder 3 Right click on your GPIB interface and select Properties from the drop down menu that appears EDVR Error Condition with ibentl Set to 0xE0140025 535560155 If a call is made with an interface number that is not within the range of allowed interface numbers typically 0 to 3 an EDVR error condition occurs with ibcnt1 set to 0xE0140025 National Instruments Corporation D 1 NI 488 2 User Manual for Windows Appendix D Windows Me 98 95 Troubleshooting and Common Questions EDVR Error Condition with ibentl Set to 0xE0140035 535560139 If a call is made with a device name that is not listed in the logical device templates that are part of t
151. uf Write data ibwrta wrtbuf Write data asynchronously ibwrtf flname Write data from a file where 1name is pathname of file to write Table 6 3 Syntax for Multi Device NI 488 2 Calls in Interactive Control Syntax Description AllSpoll addrlist Serial poll multiple devices DevClear address Clear a device DevClearList addrlist Clear multiple devices EnableLocal addrlist Enable local control EnableRemote addrlist Enable remote control FindLstn padlist limit Find all Listeners FindRQS addrlist Find device asserting SRQ PassControl address Pass control to a device PPoll Parallel poll devices PPollConfig address dataline lineSense Configure device for parallel poll PPollUnconfig addrlist Unconfigure device for parallel poll RcvRespMsg count termination Receive response message ReadStatusByte address Serial poll a device Receive address count termination Receive data from a device NI 488 2 User Manual for Windows 6 8 ni com Chapter 6 Interactive Control Utility Table 6 3 Syntax for Multi Device NI 488 2 Calls in Interactive Control Continued Syntax Description ReceiveSetup address Receive setup ResetSys addrlist Reset multiple devices Send address buffer eotmode Send data to a device SendCmds buffer Send command bytes SendDataBytes buffe
152. unt is reached If the EOS read method is disabled ibrd ibrda and ibrdf calls terminate only when the GPIB EOI line is asserted or the specified count has been read You can use the ibconfig function to configure the software to indicate whether the GPIB EOI line was asserted when the EOS byte was read in Use the IbcEndBitIsNormal option to configure the software to report only the END bit in ibsta when the GPIB EOI line is asserted By default END is reported in ibsta when either the EOS byte is read in or the EOI line is asserted during a read High Speed Data Transfers HS488 National Instruments has designed a high speed data transfer protocol for TEEE 488 called HS488 This protocol increases performance for GPIB reads and writes up to 8 Mbytes s depending on your system HS488 is a superset of the IEEE 488 standard thus you can mix IEEE 488 1 IEEE 488 2 and HS488 devices in the same system If HS488 is enabled the TNT4882C hardware implements high speed transfers automatically when communicating with HS488 instruments If you attempt to enable HS488 on a GPIB interface that does not have the TNT4882C hardware the ECAP error code is returned Enabling HS488 To enable HS488 for your GPIB interface use the ibconfig function option IbcHSCableLength The value passed to ibconfig should specify the number of meters of cable in your GPIB configuration If you specify a cable length that is much smaller than what you a
153. ure the NI 488 2 software to use up to 100 logical devices The default number of devices is 32 Are interrupts and DMA required with the NI 488 2 software Interrupts are required but DMA is not How can I determine if my GPIB hardware and the NI 488 2 software are installed properly Run the NI 488 2 Troubleshooting Wizard To do so select Start Programs National Instruments NI 488 2 Explore GPIB Then select Help Troubleshooting NI 488 2 Troubleshooting Wizard How can I start communicating with my GPIB instrument For simple instrument communication use the NI 488 2 Communicator For instructions on how to use the NI 488 2 Communicator refer to the Basic Communication Query Write Read section in Chapter 2 Measurement amp Automation Explorer When should I use the Interactive Control utility You can use the Interactive Control utility to test and verify instrument communication troubleshoot problems and develop your application For more information refer to Chapter 6 Interactive Control Utility NI 488 2 User Manual for Windows E 2 ni com Appendix E Windows 2000 NT Common Questions How do I use an NI 488 2 language interface For information about using NI 488 2 language interfaces refer to Chapter 3 Developing Your NI 488 2 Application What do I need to know to communicate properly with my GPIB instrument Refer to the documentation that came with your instrument The command sequences that you
154. urement amp Automation Explorer 2 Expand the Devices and Interfaces directory by clicking on the next to the folder National Instruments Corporation 6 1 NI 488 2 User Manual for Windows Chapter 6 Interactive Control Utility 3 Right click on your GPIB interface and select Interactive Control from the drop down menu that appears For help on any Interactive Control command type help followed by the command For example type help ibdevorhelp set 4 Open either an interface handle or device handle to use for further NI 488 2 calls Use ibdev to open a device handle ibfind to open an interface handle or the set 488 2 command to switch to a 488 2 prompt The following example uses ibdev to open a device assigns it to access interface gpib0 chooses a primary address of 6 with no secondary address sets a timeout of 10 seconds enables the END message and disables the EOS mode ibdev enter board index 0 enter primary address 6 enter secondary address 0 enter timeout 13 enter EOI on last byte flag 1 enter end of string mode byte 0 ud0 3 Note Ifyou type a command and no parameters Interactive Control prompts you for the necessary arguments If you already know the required arguments you can type them at the command prompt as follows ibdev 0 6 0 13 1 0 udo 3 Note If you do not know the primary and secondary address of your GPIB instrument right click on your GPIB interface in Measurement
155. ve multiple Controllers on the GPIB but only one Controller at a time can be the active Controller or Controller In Charge CIC The CIC can be either active or inactive standby Control can pass from the current CIC to an idle Controller but only the System Controller usually a GPIB interface can make itself the CIC National Instruments Corporation A 1 NI 488 2 User Manual for Windows Appendix A GPIB Basics GPIB Addressing All GPIB devices and interfaces must be assigned a unique GPIB address A GPIB address is made up of two parts a primary address and an optional secondary address The primary address is a number in the range 0 to 30 The Controller uses this address to form a talk or listen address that is sent over the GPIB when communicating with a device A talk address is formed by setting bit 6 the TA Talk Active bit of the GPIB address A listen address is formed by setting bit 5 the LA Listen Active bit of the GPIB address For example if a device is at address 1 the Controller sends hex 41 address 1 with bit 6 set to make the device a Talker Because the Controller is usually at primary address 0 it sends hex 20 address 0 with bit 5 set to make itself a Listener Figure A 1 shows the configuration of the GPIB address bits Bit Position 7 6 5 4 3 2 1 0 Meaning 0 TA LA GPIB Primary Address range 0 30 Figure A 1 GPIB Address Bits With some devices yo
156. x C Error Codes and Solutions EDVR 0 Solutions ECIC 1 EDVR is returned when the interface or device name passed to ibfind or the interface index passed to ibdev cannot be accessed The global variable ibcnt1 contains an error code This error occurs when you try to access an interface or device that is not installed or configured properly EDVR is also returned if an invalid unit descriptor is passed to any traditional NI 488 2 call Possible solutions for this error are as follows Use ibdev to open a device without specifying its symbolic name Use only device or interface names that are configured in the NI 488 2 Configuration utility as parameters to the ibfind function Use the NI 488 2 Troubleshooting Wizard to ensure that each interface you want to access is working properly as follows 1 Select Start Programs National Instruments NI 488 2 Explore GPIB 2 Select Help Troubleshooting NI 488 2 Troubleshooting Wizard The Troubleshooting Wizard tests your GPIB interface and displays the results Use the unit descriptor returned from ibdev or ibfind as the first parameter in subsequent traditional NI 488 2 calls Examine the variable before the failing function to make sure its value has not been corrupted For more troubleshooting information refer to the Troubleshooting EDVR Error Conditions section in Appendix D Windows Me 98 95 Troubleshooting and Common Questions NI 488 2 User Manual
157. xecute function n times where function represents the correct Interactive Control function syntax n l Execute previous function n times filename Execute indirect file where filename is the pathname of a file that contains Interactive Control functions to be executed buffer option Set type of display used for buffers Valid options are full brief ascii and off Default is full q Exit or quit Status Word Error Inform In the Interactive Control utility all NI 488 2 calls except ibfind and ibdev return the status word ibsta in two forms a hex value in square brackets and a list of mnemonics in parentheses In the following example the status word is on the second line showing that the write operation completed successfully ud0O ibwrt IDN 0100 cmpl count 5 udo For more information about ibsta refer to Chapter 3 Developing Your NI 488 2 Application ation If an NI 488 2 call completes with an error the Interactive Control utility displays the relevant error mnemonic In the following example an error condition EBUS has occurred during a data transfer ud0 ibwrt IDN 8100 err cmpl error EBUS count 1 udo NI 488 2 User Manual for Windows 6 10 ni com Chapter 6 Interactive Control Utility In this example the addressing command bytes could not be transmitted to the device This indicates that either the GPIB device is powered off or th
158. yntax seserian e K E R N a 6 4 SWINGS ynta R varias eve eee ae E N Se ea 6 4 Address Syntax sipeer u i ea anena a eid h ENEA ES 6 5 Interactive Conttol CommandS isnsissisii ienn Rei E E R EEEE EE EN 6 5 Status Word e ninoi ea a E ET TE teste E E A A 6 10 Error Information eneore ee EE EE eS AA AAA AREATA TEES 6 10 Count Information eseu e nE EE EEE EE EE E E EANET SS 6 11 National Instruments Corporation vii NI 488 2 User Manual for Windows Contents Chapter 7 NI 488 2 Programming Techniques Termination of Data Transfers 0 0 0 cece eee eseeecesececeeseeseeeseseeeesecseeesesaecesecaeenaeeaeenaeaes 7 1 High Speed Data Transfers HS488 0 cece eee ceceseceeeeseceecesecseeeaesseeeaeeeeeaseeenaeaes 7 2 Enabling HS488 i2 42 cn2h5 aictA lh eis thee eA tied ae 7 2 System Configuration Effects on HS488 000 eee ceeeseeseeeseceecesetseeeaeenees 7 3 Waiting for GPIB Conditions sisne a A a R 7 4 Asynchronous Event Notification in Win32 NI 488 2 Applications 0 eee 7 4 Calling the ibnotify Function 00 cece eeeeseceeeeseesseeseceeeeaeeeeeeaeeneeeseeenees 7 4 ibnotify Programming Example eee eee ceeeeeseceeesseeeeeeseceeceaeeseeeaeeeenaes 7 5 Writing Multithreaded Win32 NI 488 2 Applications 0 eeeeseceeeeeeeeeeeeeees 7 9 Device Level Calls and Bus Management 0 eee ee eeeeseeseceseeseeeseeeeeseessenseeseenaeeaes 7 11 Talker Listener Applications 00 0 hareen anren rE Aae E A r EE A EEE ETRA AR 7 11 Senal POIDS era erer

NI-488.2 User Manual for Windows

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