OpenTAP removes configuration items

Technical
,
1

Hello again,

I am running into some cases where OpenTAP “helpfully” removes instruments from the configuration that it can’t find because they are disconnected or powered off. Is there a way to change this behavior to error and stop testing instead of trying to test by removing the configured item and then giving errors because the test steps reference something that doesn’t exist? I honestly find it a bit absurd that it changes the bench configuration files at all. Those should be read-only to OpenTAP.

Will it do this to DUTs too? Our DUTs are never powered until after the setup phase of testing is complete (checking for shorts and opens, etc). It would be particularly bad if it removed the DUTs before the test even began.

2

Hi @matthewdumas,

I don’t recognize the exact problem you are mentioning here. OpenTAP will not remove resources, just because they are powered off or disconnected.

It makes me wonder if you have some plugin that does this.

Something I know happens is if you load a test plan that depends on resources that are not defined in your settings, but I believe this is different from what you describe.

Can you provide a path to reproducing what you are describing?

3

I’ve got the PathWave ks8000a license. Any time I add a device and then run a TapPlan, it deletes the device if the device isn’t immediately available at runtime.

For me, this happens every time. I originally set Instruments.xml to read-only so it wouldn’t, but once I deployed in my test runner that read-only flag caused OpenTAP to throw errors.

You’re making me think this might be a Keysight problem. I haven’t used OpenTAP without it because I’ve been developing tests and a test runner in parallel.

4

I am not denying that you have found a bug, but I still don’t completely understand the setup.

Can you provide steps to reproduce it?

5

For a while now, everything (instruments.xml, connections.xml, and duts.xml) has been set to read only, and I have not had the issue. I only asked this question because in doing the same with my home-brew test runner it crashed on every settings load until I changed them to read-write mode.

I just tried to reproduce the instruments xml issue and I couldn’t. It may be a solved issue.

Regardless, I’ll keep an eye on it and make another post if it happens again. Typically, this is what would happen:

  1. I setup a standard Instruments.xml file for all of my benches - they all have the same hardware.
  2. Move Instruments.xml to the Settings/Bench/Default folder.
  3. Forget to plugin a device
  4. Run the TapPlan in Pathwave
  5. Receive “Can’t find X instrument error”
  6. Open Pathwave’s configuration editor and observe that at least 1, but typically 3 or more devices have been removed from the configuration.
  7. Open Settings/Bench/Default/Instruments.xml and observe that those devices have been completely removed from the file.

If I were to write tests for this it would be the following:

  1. Open Pathwave Configuration editor
  2. Add any type of device that doesn’t exist/isn’t connected
  3. Click ok.
  4. Create a TapPlan using the device
  5. Save tapplan
  6. Close Pathwave
  7. Open Pathwave
  8. Verify device exists in configuration editor
  9. Open TapPlan
  10. Run TapPlan
  11. Verify device exists in configuration editor

The second test case would be to manually edit the xml to add a fake device, copy the xml to your bench settings. Then follow the instructions starting at #4 with your favorite test runner instead of pathwave.

Hopefully, this is no longer an issue. I may have been putting the cart before the horse asking about it.