find VISA resource error only when using output terminals (-1073807343)

[Roberteh]

When I run the "VISA find resource" vi with only error in and error out wired, error out reads "no error". This is the case regardless of whether there are controls wired to the block

If I run the "VISA find resource" vi with either of the other two output terminals wired to anything (indicator, while loop with nothing in it, etc.) an error comes up with the error code -1073807343. 

I've attached two screenshots of the states I described above. I haven't attached a VI since this seems to be computer specific. I've tried running a VI built on my machine with another computer and it ran fine.

Has anybody experienced this before? I've never seen anything where reading from a VI changes how the VI functions.

I'm running LabVIEW 2018 on a windows 7 machine, I can post other specs if people think they'll help.

[RavensFan]

Are you sure VISA is installed okay in the PC giving you problems?

Are you sure you have a serial port on the PC giving you problems.  I'm thinking if that you don't have a serial port (serial is much less common on PC's nowadays), there are no resources to return the information about.

The reason it may work when nothing is wired up to the is that perhaps the compiler throws out the code since it knows you aren't doing anything with the outputs.

[Roberteh]

According to NI MAX I have the latest version of NI-VISA 18.5 and NI-VISA Runtime 18.5 (not that i expect runtime to be the problem). So far as I can tell it's working fine, I just installed LabVIEW on this machine yesterday. I can try reinstalling VISA to see if that helps. I'll report back on that.

When you say serial port do you mean the physical 9 pin port or a software thing? I can't find a physical serial port, but I know I've run the VISA vis using USB ports for serial communication and they work just fine.

Thank you for explaining what's probably up with the difference between wired and unwired. That was worrying me a bit.

[Roberteh]

Update - Installing VISA 18.5 again didn't change anything. Same error, same symptoms

[RavensFan]

I was thinking any kind of serial port.  PC's rarely have a built in serial port.  So if you didn't add one through a USB adapter, you'd have none, and I was thinking that was the cause of the problem.

Check to make sure the serial ports show up in Device Manager without any errors.

There is an input to the Find Resources that is an enum for different types of ports.  Create a constant on that terminal and try different options to see if any of them work.