niveristand-python: Use a ChannelReference as parameter

[joe_JD]

Hello all,

I am currently working on a project using NI VeriStand 2021 R2, doing some RT measurements using niveristand-python.

The task is to measure the on-duration of several analog input channels of a PXI system.

To make my code reusable I am searching for a way to set the input channel as a parameter of the function that is calculating the on-duration.

As far as I understand, I would need to set a ChannelReference as a parameter...By now I was not sucessfull.

Does anyone have some suggestions for this?

Thank you!

PS: attached is some example python code that is working but using a fixed channel

[ZYOng]

If you want to reuse the python script on different VeriStand projects, you should configure all those VeriStand projects to have the same channels name.

[joe_JD]

Well, ok...

But how can I handle different channels in the same VeriStand project without hard-coding them into the python module?

Any ideas?

Thank you.

[ZYOng]

You can use the user channels. Hard code the user channel name in the python script, then change the mapping in VeriStand project as needed.

[joe_JD]

Thank you @ZYOng for your reply.

I know I can also go with the user channels. But hard coding is not the solution I am looking for.

However, it seems there is no other way for handling this problem.

[RGSchmidt]

Hello ... Did you ever find a workaround for this ... I am trying to do the same thing but the Python implementation for Veristand is very limiting as well as incredibly non-pythonic.

Thanks

Randy

[joe_JD]

Hi,

yes I found a workaraound.

I wrote a small python script that modifies the real time sequence file (it's an xml file). It changes the Default Channel to the channel I want to test.

I am then calling this script cyclically from within a TestStand sequence.

Regards

Johannes

[RGSchmidt]

Do you mean you are changing the 

<Channel Path="Hardware/Truck_Hardware_Aliases_3WS/CAN1_state" />

based on the 

<Identifier>ch_can1_state</Identifier>

There has to be a better way.

Within TestStand they use the concept of FileGlobals, I am trying to figure out the equivalent in the Python implementation.