I have problems getting readings from an Agilent 34401 using the LabView drivers from the IDN. I get VISA timeouts, error code is -1073807339.

[thehobbs]

You can try updating the firmware on the instrument, although I admit this is a bit of a stretch for solving this particular problem.  But it is pretty easily and might be worth the attempt.  Just check Agilent's site for details of upgrading the firmware.

[7drb]

I've been having the same problem that Matthias originally reported.  I have two test stations that have the 34401A interfaced via a PCI-GPIB card.  I'm running XP and use LabVIEW 7.1 and TestStand 3.1 for my development environment.  The problem is that on one of the stations (my development station) everything works the way I expect it to.  On the station that I have to send to the CM (contract manufacturer), I consistently get this time out error (after the default 20 seconds programmed in the driver I downloaded from the IDN site).  The only difference between the stations is that the one going to the CM has a TestStand Deployment package instead of the complete development environment.

A month or so when I started on this project, I had the same error on my development station but the problem just "disappeared" one day.  I'm not sure what I did or what happened to make it go away.  The second station was put together a few days ago and this problem popped up again.  I can't troubleshoot the problem on my development station because it isn't there anymore and I really don't want to install all the development software on the second station.

It seems that many people on this forum have encountered this issue but I can't seem to find any information about the root cause of the problem nor a solution.  I'm going to try swapping my 34401As between the two stations on Monday but I don't think it will help.  Any help or insight would be greatly appreciated.

Message Edited by 7drb on 11-25-2006 09:48 AM

[Adam W]

Hi,

Do you get the same behavior if you run the code directly on the CM station rather than through TestStand?  Also, are there any differences in the two computers that would be relevant?  Could it be that one computer is performing more quickly than the other?

Thanks!

Adam W
Applications Engineering
National Instruments

[7drb]

Hi Adam,

Thanks for your reply!!  The code is setup so that the 34401 is initialized in the Startup and closed in the Cleanup in the TestStand environment.   A VISA Resource is passed to each step of the sequence that requires the DMM.  I thought it was more efficient and better coding to do it this way rather than repeatedly opening and closing the instrument.  This means I can't easily run the code on it's own on the CM station.  I also do not have the development environment installed on the CM station and I'm reluctant to put it on as I have a couple more stations to setup for the CM after this one is finished.  The computers are essentially the same (Intel P4) so I don't think computer is the issue.  I tried upgrading the VISA drivers to 4.0 yesterday but the problem is still there.

The test times out the first time I run it, so I terminate the test sequence by running Cleanup.  The details are:

    VISA Wait on Event in Wait for RQS.vi->HP34401A ReadMeas.vi

    VISA: (Hex 0xBFFF0015) Timeout expired before operation completed.

I rerun the test sequence again and during initialization in the Startup, it reports error code -107400165.  The details are:

    <ERR>HP34401A Error Query:

    instrument reports:

    -410, "Query INTERRUPTED"

I then terminate the sequence by running Cleanup.  I rerun the test sequence again and the cycle repeats where the 34401A times out.  The pattern is consistent.

[Jim Piotrowski]

Hi!

I tested the driver using an identical setup as the screenshot earlier in the thread and it worked...at first.  After tweaking some settings, I started finding the same timeout issues as everyone else in the thread.

I've looked into the issue and it seems that the service request mechanism isn't working correctly.  The Wait for RQS VI throws a timeout and that's what's causing the error.  The data stays in the buffer, causing a Query Interrupted (-410) error to occur on the next run.  We've since moved away from service requests in the project-style driver, so the newer 34401 driver should work fine (as well as being coded more efficiently).

Anyway, I rewrote a bit of the code, and it seemed to fix the issue on my machine.  If you replace the Read Measurement driver VI with the VI I've attached to this post, it should (I hope) fix the issue on your setup as well.  This version uses the Operation Complete bit on the instrument and then polls it until the operation is complete.

If you implement this VI, please leave feedback telling us if it helped or not.  If it seems to help, we may look at upgrading the 7.0 driver with the fix.

Thanks!

[7drb]

Hi Jim,

Many thanks!!  I tried the VI late this afternoon and my application now works as expected!!  If I ever make it to a NI Week, I think I owe the Apps group a round on me.  Thanks again for your help!

Darby

p.s.  I wonder if this would help all those other Agilent instruments that have timeout issues...

[Gav]

Hello,

 

I have an Agilent 34401A connected to my PC (running LabView 8.6) via a serial/USB adapter.  When running the ‘Agilent 34401 Read Single Measurement’ example driver I get the -1073807339 timeout error mentioned in this (and several other) thread(s).

 

The error occurs at the Initialize SubVI.  When I wire a false constant to the Reset terminal of the Initialize SubVI it completes without the error.  However, the timeout returns at the Measure SubVI.

 

When I open that SubVI and turn on the highlight tool, then return to the example VI and run it, I successfully read the measurement from the meter.  With the highlight tool turned off I get the timeout error every time.

 

Could this be a timing issue that comes from using the serial/USB adapter?