EAB0 error with repeated reads or writes on PCI-GPIB

[jhgreben]

I've been trying to interface 3 reasonably old instruments (Keithley 224, Keithley 182, LakeShore DRC-91C) with a slightly newer computer (Gateway 366c) running Windows 2000 with PCI-GPIB (NI 488.2 version 2.42). The instruments used to correctly work on a computer using a GPIB-PCII and MSDOS. Everything seems to be working correctly, I can query all the instruments with IDN and everything responds, and ibwrt and ibrd work, but if I send a 2nd write or read to an instrument after it has reponded to the previous request, I get an EAB0 error.

I've tried changing the timeout time, waiting longer between commands, and different bus timings, but it continues to happen.

If anyone has any ideas I'd really appreciate it.

[Albert.Geven]

Hi

I would put the bustiming to 2 microseconds and disable autopolling.

The last one you did not mention yet.

[jhgreben]

Just tried that, still getting EAB0.

[Albert.Geven]

How long are your cables, and what about swithed off systems?

These systems should work but sometimes a cable/connector is a bit rusty after all those years.

I really have no clue other than these.

[Snowman 6008]

Is there anything you can do to make the system work? You said if you do an IDN that it works, but any subsequent writes result in an error. What do you have to do to be able to communicate to the instrument again, restart the system, wait for an hour between each ibwrt?

Do you still have the programs and can you install them on the new computer? (Trying to figure out if the problem follows the new hardware or the new software). If you can get a NI-SPY capture of the DOS system, or a system with dos on it, we could compare to make sure that we're writing the same commands.

[jhgreben]

Total cable length is maybe 6 feet, I don't think it should be a problem considering it worked before. The connectors don't appear to be rusted, and I don't think this explains why it always times out on the second read.

I have the old software and it runs fine on the new computer now besides getting the EAB0. I discovered the problem wasn't the software when I tried doing reads and writes in MAX and the problem came up (I also initially thought it was just 1 instrument, but all of them do the same thing). What is strange is after timing out on the second read or write, it will work fine again. It basically alternates between EAB0 and working just fine.

As for comparing to the old dos system, unfortunately that machine has been broken for years and isn't even around anymore, and I am not sure I can find one with a GPIB-PCII card.

Is it possible that the problem is something with PCI bus mastering or the way the card is installed? I tried to check the bios on this machine but unfortunately I couldn't find any setting for PCI bus mastering.

[Snowman 6008]

So if i understand you correctly after you get the EAB0 error it works for the next read/write cycle. It doesn't matter if you read/write immediately or let it sit for an hour, you get the same functionality. Can you take a spy capture of a few read/write cycles http://digital.ni.com/public.nsf/allkb/282C5D41E2BA04F2862574BA007803B9 using only the VISA test panels and issuing the IDN command?

[jhgreben]

Here's the log file. I wasn't getting the error with the IDN command so I did a few reads to reproduce the error.

[Snowman 6008]

It doesn't look like you're passing the same parameters into the ibrd on the items that pass as the items that fail.

[jhgreben]

If I'm not mistaken, what is in the quotes is the information returned by the instrument. I'm using the same read command each time with a bytecount of 28 (ibrd 28 in IBIC).