Why is my NI Spy not picking up anything?

[RHL]

I have tested communication with GPIB. It works fine, and my application is running successfully over the GPIB. However, I can't get my NI Spy to capture the GPIB commands. Why?

[Kim L]

Are you clicking on the blue arrow or going to "Start Capture" under "Spy"? Are they greyed out or are you able to click on them and nothing happens. Try opening up NI-Spy, starting the capture, then opening MAX and Scanning for Instruments. That should show some commands on the GPIB.

If that doesn't work, you may consider upgrading or downgrading your GPIB driver. You can get to the driver versions by going to:
http://www.ni.com/support/gpib/versions.htm
Also, make sure that you do not have 2 versions of the GPIB driver in your machine. LabVIEW and CVI install NI 488.2 by default.

In order to troubleshoot further, I would need more information about what GPIB interface you have (GPIB-USB-A, PCI-GPIB, etc.), what driver you are using, and your operating system. If
these suggeestions do not get your NI-Spy running, contact us either by phone or email support. The information is given at the following website.
http://sine.ni.com/apps/we/niae_asc.main

Have a great day.
Kim L.
Applications Engineering
National Instruments

[RHL]

Thanks for the reply. Actually, we finally got it going. The reason was that our application was running as a service in the Windows NT environment talking through GPIB to the instrument. NI Spy was not able to capture commands in this environment.

When we changed from running the application as a service to an executable, NI Spy was able to capture the commands. Is there a reason for this?

Ray