GPIB ports were no longer listed within the GUI

Paul · August 19, 2026, 8:16am

Hello,

For about a month now, we’ve been testing the SweepMe software in our department with a view to possibly using it for an upcoming new hardware purchase. So far, we’ve successfully connected three different devices and performed measurements, and overall we’ve been quite satisfied with the software.

Unfortunately, about two weeks ago, we experienced a problem similar to the one BMTUB (Benjamin) had already described in November:

The GPIB ports were no longer listed within the GUI. Devices with a LAN connection, however, were still recognized.

Since no changes were made to the VISA drivers at that time, and the measurements had been working previously, we do not believe the issue lies with the VISA driver itself. The .DLL files in the respective folders were also last modified before the initial installation of SweepMe.

Unfortunately, uninstalling and reinstalling the software did not resolve the issue. The same applies to an update of the SweepMe software.

We were also able to rule out a pyvisa issue, since the resources for the GPIB connections are recognized correctly and completely. Communication with the devices via pyvisa outside of SweepMe is also possible (gpib_pyvisa.py, Find_port_sweepme.py for the SweepMe folders and self written trest scripts).

One possibility we suspect is that the list of GPIB connections is no longer being passed within the GUI program.

Is there a way to check this, or do you have any other ideas on how to restore the system to its original state after inital nstallation?

Thank you very much and best regards,

Paul

Axel · August 19, 2026, 11:14am

Hello Paul,

thank you for creating this issue and taking the time to describe the problem. Sounds like a new problem that differs to the one from Benjamin:

If you can use python scripts and you can see LAN connections from the VISA runtime, it is clear that your VISA runtime seems to work.

Also if you can use GPIB ports in own python scripts, the VISA driver for the GPIB adapter or card seems to be ok.

I guess you are using SweepMe! 1.5.8.8 if you just recently started to use SweepMe! and made an update.

You wrote that you have used the script gpib_pyvisa.py
Did you run it in your own Python environment or did you run it with the Python Script Tool?

You can go to menu “Tools” → “Python script” to run these scripts within the Python environment of the SweepMe! executable:

Please test the scripts gpib_pyvisa.py and visa_debug_info.py.
If you run them, the output is shown in the Debug widget (key F2).

Can you send the output. It will be interesting to see which VISA runtime is detected and whether the script can find GPIB ports. You can also modify the script to show all VISA resources (not just GPIB).

Maybe this already helps us to figure out.

You could also cross-check whether there is any python script or other application that is maybe already holding direct accces to the GPIB ports.

If this does not give us a clue, I can offer you to meet in a video meeting and debug it together as this is a severe issue that should not happen and we have big interest to figure out what is going on.

Thanks a lot and best
Axel

Paul · August 19, 2026, 1:27pm

Hi Axel,

Thank you very much for your quick response and the tip to run the script via your SweepMe Console!

It actually seems that the Python versions themselves differ between SweepMe and VS Code, where I had tested the scripts previously. Also the absolute path of the Executable is different as well as the Compiler.

As a result, the PyVisa version isn’t recognized in SweepMe.

Is there a way to make PyVisa accessible to the SweepMe software retroactively, or should we move PyVisa to a virtual environment for “external use” and install SweepMe again?

Thanks again for the great advice! I think we’re getting closer to a solution.

Best regards,

Paul

Axel · August 19, 2026, 1:58pm

Hi Paul,

SweepMe! comes with its own Python environment including a matching pyvisa version. So, it does not rely on your own Python or pyvisa installation.

The fact that the Pyvisa version is not shown in SweepMe! is expected. When pyvisa is shipped it with an executable, its version number is not correctly determined. It think this is because the version number is dynamically created that breaks in executables:

github.com/pyvisa/pyvisa

pyvisa/init.py

e3faa8e1d


      
                  "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
              )
          
              ch.setFormatter(formatter)
          
              logger.addHandler(ch)
          
          
          __version__ = "unknown"
          try:
              __version__ = version(__name__)
          except PackageNotFoundError:
              # package is not installed
              pass
          
          
          __all__ = [
              "Error",
              "InvalidBinaryFormat",
              "InvalidSession",
              "LibraryError",

From the credits file of SweepMe! 1.5.8.8. it should be version 1.13.0.

Independent from the missing pyvisa version number, the script can find a visa32.dll file at C:\Windows\system32
which is the same path and file that you have in your Python 3.14 environment. That is already good.

What you could try as well:

When you click “Find ports” in a module, do you see any debug message?
When go to “Tools” → “Port manager” → button “Find all ports”, do you see any debug message?
We just have released a closed beta of SweepMe! 1.6 that comes with Python 3.14.
https://forum.sweep-me.net/t/sweepme-1-6-beta-the-test-phase-is-starting/284
Could you download this version from the account and test it? It also comes with a newer pyvisa version.
Can you unplug and reconnect the GPIB adapter?

I don’t think that is a problem of SweepMe! 1.5.8 or its pyvisa version as it runs at other setups with no problems. If pyvisa would not work at all, you would also not see any TCPIP connections.

Still, there is something that hides GPIB ports at your setup. If the above questions do not help, we should have a short video meeting and check your setup. I will send you a message.

Thanks and best
Axel

Paul · August 20, 2026, 7:52am

Hello Axel,

Thank you very much again for the new tips.
Installing the BETA version 1.6.1.2 has resolved the problem.

Here’s a slightly more detailed account of my attempts in response to your last post:

When you click “Find ports” in a module, do you see any debug message?
- Before clicking “Find Ports”
  
  After clicking “Find Ports”
  
  grafik817×107 11.9 KB
- No Debug message
When go to “Tools” → “Port manager” → button “Find all ports”, do you see any debug message?
- Noting happens at clicking
- No debug message
We just have released a closed beta of SweepMe! 1.6 that comes with Python 3.14.
SweepMe! 1.6 Beta: The Test Phase Is Starting
Could you download this version from the account and test it? It also comes with a newer pyvisa version.
- LCR-Module was needed to reinstall
- After doing this the test for LCR-Meter GPIB-Connection was working
  
  grafik625×391 52.5 KB
- Port manager now finds also all GPIB-ports
  
  grafik625×194 15.4 KB
- A test run without a sample could be performed
Can you unplug and reconnect the GPIB adapter?
- Not tested

Axel · August 20, 2026, 8:09am

Hi Paul,

thanks a lot for performing the tests. It is nice that it works with the new version, but still strange that 1.5.8.8 has the problem at your setup.

If you are about to get started with SweepMe! and you are setting up first measurements, you can go ahead with SweepMe! 1.6.
I don’t expect any breaks in your setting files when you later install the released version of SweepMe! 1.6.

And we anyway plan to release it in the beginning of September and just do some fine adjustments and further testing. Any feedback is of course welcome.

Thanks a lot for performing the tests!
Best, Axel