Does the AT-GPIB/TNT under NI488.2 require interrupts for Windows-ME?

[pblase]

I'm trying to use an AT-GPIB/TNT board under Windows-ME, to talk to an HP 3562A signal analyzer; trying to use MAX at the moment, but getting the same symptoms under Labview also. The 3562A appears to receive the command, but the software times out and never gets the reply. I had to disable the interrupt when installing the board (at the request of the Add-GPIB-wizard). The help file says that interrupts aren't required under Windows 95/98, but are under 2000/NT. How about ME?

[Randy Solomonson]

Hello-

Windows ME is just a newer version of Windows 98, so it's probably not the case.

The EABO error results from a timeout on the bus. Since this is happening on the read there are a couple things I might suggest you look for:

-Did the instrument understand the command you sent it? If you write *IDN? to the instrument but it does not recognize that command then it will not return data causing an EABO on the read. Try finding an alternate command to issue that will return data. A list of commands should be found in your instrument's documentation.

-Are you terminating the communications correctly? If the instrument requires an end of string character but you are not sending it then the instrument is going to hang. It does not know th
at it has all of the data so it will continue reading from the bus. When the controller goes to read, the instrument has not put any data on the bus to read so again, it times out. Termination methods can be determined in your instrument's manual and tweaked from the GPIB Configuration utility located in your Control Panels.

-Run NI-SPY in the background. This program logs all of the GPIB calls. We can use this to generate a log of the action on the bus. Run this program in the background and generate a log file to look through to see if you notice any suspect commands being issued. Feel free to enclose an NI-Spy capture file on subsequent responses.

[pblase]

Tried all variations on terminating the communications, no dice. The manual is somewhat vague, but none of the examples (which are in Basic) show terminating characters. The ID request is "ID?".

[Randy Solomonson]

It looks like the write is actually timing out. This could be due to cabling errors, or the instrument is not responding to GPIB command at all. Does the instrument appear in MAX? Does it appear in VISAIC? If so, what is the primary address (PAD)?

Randy Solomonson
Application Engineer
National Instruments