General Troubleshooting Tips for VISA problems

Sunday, August 12, 2012

First Steps

Go to a New VI.
Go to the block diagram.
Put the VISA Find Resource.vi on the diagram. (It's in functions palette >> Instrument I/O >> VISA).
Pop-up on the VI and create a control for Search Expression.
Pop-up on the VI and create an indicator for Find List.
Your block diagram should now look like this:
Go to the front panel and type "?*Instr" in the expression control.
Pull down on the find list array so that 6 or more elements are showing.
Your front panel should look like this:
Now click on the Run arrow. You should at least see your serial ports after it runs. My serial port data looked like this:
The ASRL1 is com1, ASRL2 is com2, and ASRL10 is LPT1
If the serial ports aren't found, VISA was not installed correctly (or not installed at all). You should reinstall it. Click here to go to a page from which you can download NI-VISA.
If the serial ports are found, VISA is working fine. (However, the GPIB stuff may not be totally configured). If this is the case, there are five possible reasons why:
1. Instrument not turned on.
2. Cable not connected, or is bad.
3. GPIB card not present in computer (or not properly seated).
4. NI-488 driver (the driver that runs the GPIB card) is not installed.
5. NI-488 driver is mismatched with VISA driver (one is 16-bit and the other 32-bit).
If VISA is working fine, and GPIB ports are found, then go to this page to check on possible solutions for VISA errors.
If GPIB ports are not found, we must do GPIB troubleshooting.