GPIB Synchonization with DAQ

[ChromaBurst]

Currently I'm in the position of implementing a software-timed solution so that my data acquistion hardware (analog inputs) can be synchronized to an average reponse time for a GPIB query to an instrument. Yes, this sounds like fun! I was wondering, I seem to remember the GPIB analyser software (CVI app) had timing information for the various line state transitions. In general, is there any way to get hardware timing information from a NI GPIB controller?? The reason for this approach is that the DAQ AI samples may be corelated to the instrument data - we don't know at present!

[Randy Solomonson]

Hello-

The GPIB analyzer software does have a triggering menu available. However, there is currently no API for the analyzer available. However, it might be possible to tap the EOI line with a second GPIB cable. Then, a DAQ card can monitor the progress of the GPIB communication. There may be some easier software solutions as well. Try using Datasocket if it is necessary to have interprocess or intermachine communication. There are plenty of Datasocket examples in CVI and LabVIEW.

Randy Solomonson
Application Engineer
National Instruments

[ChromaBurst]

Thanks Randy, I liked your approach for breaking-out the EOI line. However, I think you missed the point of the question - "Is there any way to get hardware timing information from a NI GPIB controller?"

[Randy Solomonson]

The GPIB+ boards do have some special analyzer hardware. However, to gain access to this hardware is non-trivial. There is currently not an API to gain access to this hardware. There's not even a driver available yet for this portion of the card in Windows 2000. With this in mind it would be necessary to develop a driver and API, then the end application. This is a very long and painful road. Breaking out the lines to a DAQ card is probably much easier.