GPIB interrupts Linux process in telnet

[j. smith]

1. TestStand uses LabView to start a Linux process in a telnet window with a given session id.

2. TestStand uses LabView/ to send GPIB commands to an instrument.

3. Linux process seems to disappear, discontinuing output.

4. Upon referencing the telnet with the given session id the Linux process output resumes.

Are there known problems with VISA sessions conflicting?

[LoganS]

So is the process you are running on the Linux system have a specific purpose?  Is it working with any specific hardware?  What versions of NI-488.2 and NI-VISA are you using on your Windows and Linux systems (if applicable)?  Do you have any errors that have occurred?  What in your troubleshooting has led you to question VISA sessions?  Sorry this is just list of questions, but I don't quite understand what's going on with your system.

Logan S.

[j. smith]

Windows is running NI-488.2.2.20 and NI-VISA 3.2f1. Linux is accessed only through telnet sessions from LabView/TestStand.

The basic scenario is a Linux process is started from a telnet session in LabView/TestStand on the Windows machine that continually logs to a file. While this process continues to run, a USB to GPIB connection on the Windows machine to a switching instrument is activated through a LabView vi. Next the telnet session is again invoked through its session id. Upon checking the log file from the initial telnet start, there is a gap in it from the time the GPIB connection was made to the time the telnet is reactivated. The gap does not occur when the switching instrument is not accessed, so I am led to believe that the GPIB connection is having some effect on the log process, though it is difficult for me to imagine how.

Some things I have tried:

Running the Linux process in the background does not seem to make a difference, though starting it with the "nohup" command (for no hangup) does keep the log running; all telnet output then goes to the file nohup.out which is not really what I want to happen.

Some things I can try:

Serial instead of GPIB to the switching instrument.

I understand that this is a pretty obscure situation and problem. Thanks for taking a look at it.

Jim Smith

[LoganS]

Well, I'm not sure if it will correct this issue or not, but I would recommend upgrading to the latest versions of NI-488.2 and NI-VISA.  Even if they do not correct this error, it would put us in a better position to replicate what you are seeing.  Please let me know if this would be possible.

Logan S.

[j. smith]

Thanks for the links, I did install the new drivers. Unfortunately it did not seem to have any effect. I may try a serial connection next instead of the GPIB to see if that makes any difference. Also I may try a much reduced scenario with a different Linux process and different instrument.

Jim Smith

[LoganS]

Please let us know how that goes.  Sorry the upgraded drivers did not resolve your error.  I'll keep checking...

Logan S.