Problems connecting and reading 2 seperate HP34970

[TorbH]

Hello

For some reason I am unable to read the 2nd 34970 device. I have added 3 snippets, part of my code.

First is "connection", works fine, no errors.

2nd is ReadFAT, works fine. 3rd is ReadCal where I get error -1073807298.

If I swap the comports in the "connection" state, ReadCAL works and ReadFAT does not, making me sure it is not a connection issue.

Connection to instruments seems to be working ok, just not at the same time. The code in  ReadFAT and ReadCAL is copied, should be the same.

I am running out of ideas, is there something I am missing?

I am using virtual comports on 2 separate Ethernet Nports if that makes a difference.

Windows server 2012 r2

Tried both LV 2016 and 2017, same problem.

Appreciate any input.

[cbutcher · Accepted solution]

I put a loop around your snippet and tried to reconstruct and resize it. Is this approximately your VI? (And if not, can you upload your actual VI?)

My guess is you have a few connections that should be passed through other cases and are not. This is leading to default values being passed to your VISA connections, which then fail.

[crossrulz · Accepted solution]

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cbutcher wrote:

My guess is you have a few connections that should be passed through other cases and are not. This is leading to default values being passed to your VISA connections, which then fail.

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Not just a guess, it is exactly what is happening.  Just look at the ReadCAL and ReadFAT cases.  NONE of the tunnels are wired through.  Therefore the session reference of the other instrument is lost.

First suggestion: Turn off "Use Default If Unwired" for all of the output tunnels.  Then fix the errors with linked tunnels (which interestingly enough, you have linked tunnels but then deleted the wires in the cases).

[TorbH]

Surely you are correct.

Thanks for the input.