Prologix LabVIEW write/read error

[AM33]

Hello Daniel-E,

I have updated the VISA to 5.3 at your recommendation. I have changed the name of the port the USB is named from (COM7) to (COM4). I did that because the vi changes the COM port to 4 no matter what selection is made. I noticed this when I had the write/read vi open inside of the parent vi. I now have a new problem. I can get a Lock in to show up on my front panel graph but still get a straight line on my multimeter (O-scope). I have attached jpegs in case I am missing something obvious. Thank you very much for the configuration suggestion.

[Daniel-E · Accepted solution]

AM33,

To be clear, are you saying that at this point, one of your devices is working properly, but the other is not? Are the two graphs corresponding to separate devices, or are they both getting information from the same device?

If one device is working but another isn't, we might want to check the address of that second device to make sure it's configured properly. Another thing we could try would be to write a very simple test program (or use an example) to communicate with each device individually to verify that this is working properly.

Essentially, I think it would be wise to simplify the code a bit for testing, and to narrow down where the problem might lie.

[AM33]

Yes, they are coming from two different devices: O-scope and Lockin. The O-scope is what is not showing up. They are both being read by the GPIB due to the interface cord connection connecting the two devices. This way they are both read with the GPIB and passed through (COM4). The confusing part is that two months ago this physical set up worked. I am pretty new to LabVIEW so I am not sure what is meant by check the address. Do I check the computer side or vi side?

[AM33]

I got in touch with the gentleman who put the vi together and he said that I will have to rewrite the code for the O-scope since it is coded for multimeter. I have never done that so this will be a learning experience.

[Daniel-E]

AM33,

It definitely sounds like that might be the issue, if the code needs to be different for one of those devices. Perhaps the person who wrote the original VI can point out some of the changes that need to be made?

If you run into any problems while developing the new code, please feel free to make a new thread on the forum with those specific issues so myself and other forum users can help you out. Good luck with the development!