LabVIEW Always Sets GPIB Boards as System Controllers Primary Software: LabVIEW Development Systems>>Full Development SystemPrimary Software Version: 5.0.1 Primary Software Fixed Version: N/A Secondary Software: N/A
Problem: I am trying to write a non-controller application in LabVIEW, so I am using the SendDataBytes and the RcvRespMsg functions, which do not require me to be the System Controller (unlike the GPIB Write, the GPIB Read, the Send, and the Receive functions, which do). I used NI Spy to see which GPIB calls LabVIEW makes: ibfind GPIB ibrsc 1 SendIFC (and some other calls ...) Then, it will send the bytes that I request. The SendIFC is used by System Controllers to initialize the GPIB. I obviously do not want my non-controller acting as if it were the controller, since it would conflict with the computer that is the controller and give me an ECIC error. LabVIEW does this, even though I have configured the GPIB board to be a non-System Controller in the GPIB Configuration Utility. What's up with that? Solution: This is a feature of LabVIEW, not a bug. LabVIEW will automatically configure your GPIB board as the System Controller, even though you specified otherwise in the GPIB Configuration Utilty. The reasoning behind this is that the majority of GPIB applications are controller applications. You need to use the GPIB Initialization function at the beginning of your VI to override the default LabVIEW GPIB settings. Connect a Boolean False to the System Controller input to make it a non-System Controller. As for the GPIB Configuration Utility settings versus the LabVIEW settings, the GPIB Configuration Utility settings are always used unless they are overwritten by the LabVIEW settings (i.e., if you decide to do your configuration settings in LabVIEW). The System Controller setting is the only setting that LabVIEW changes automatically. Remember, it is good programming practice to configure your GPIB settings in your program, so that you are not at the mercy of the settings in the GPIB Configuration Utility. (For example, if you move your program to a different computer, or someone changes the settings without telling you) Related Links: Attachments:
Report Date: 01/13/1999 Last Updated: 12/09/2004 Document ID: 1HCF1CQA |
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