I cannot talk to a HP8112 function generator with GPIB.

[NancyLynn]

My USB GPIB card can detect my entire rack of instruments, but cannot detect the HP 8112 function generator(FG). (Note: I use the "Measurement and Automation Explorer" to scan for instruments.) Also, when the FG is on the bus, the other instruments also become invisible. The Explorer only detects the other instruments if the FG is disconnected from the bus. If I isolate only the FG and scan for it with the Meas & Auto Explorer, I see the FG initialize and go into remote, but the Explorer does not see it. Any suggestions?

[JoshuaP]

Hey Nancy,

It's possible that the old 8112 does not support 488.2 and therefore might not respond to *IDN?. This is a very old device. I tried to look up the information on-line, but agilent just had the general description.

http://we.home.agilent.com/cgi-bin/bvpub/agilent/Product/cp_Product.jsp?NAV_ID=-536891753.536881157.00&LANGUAGE_CODE=eng&CONTENT_KEY=1000001733%3aepsg%3apro&ID=1000001733%3aepsg%3apro&COUNTRY_CODE=US

You might want to change cables, to make sure you don't have a bad cable. It is possible that this device supports an older version of 488 or is damaged. The first thing I would suggest is finding the user manual and then try see if you can send any commands to it that it supports.

However, if the other devices are disappearing fro
m the bus its possible you will have to get a new FG if the cable check out to be good.

Best Regards,
JoshuaP
National Instruments

[Constien]

I have the same problem. Using three different 8112A's and multiple GPIB cables, MAX was never able to find it in an instrument scan. Additionally, whenever it was connected with other devices none of the devices would be shown on a scan for instruments. As soon as I would power off the 8112A�s everything would show up normally in MAX.

An interesting thing that I found was when I opened VISAIC (VISA Interactive Control) it found the 8112A and all other instruments without a problem. I believe it is something in the way MAX does its scan and the way the 8112A reports back during the queries that causes it to fail to show any instruments.