Serial ports not appearing in MAX - VISA installed.

[Sam_Sharp]

Hi All,

Had a rather strange issue today that I couldn't resolve with serial ports not appearing in MAX (and hence being inaccessible to LabVIEW). Under the windows device manager it shows 4 COM ports and I have verified with an external program that they are functioning correctly.

I had the LabVIEW 2011 SP1 f2 runtime installed, DAQmx 9.6.1 and NI-VISA 5.3 (5.2 also didn't work).

Things I have tried:

- Updating VISA from 5.2 to 5.3

- Reinstalling the COM port devices under device manager

- Changing the COM port numbers

- Verifying that the COM ports are functioning correctly

- Tried adding a USB to Serial converter as a new COM port

- Reinstalling MAX

- Reinstalling NI-VISA

- Reinstalling everything (reboot each time when prompted)

- Resetting the hardware configuration from within MAX

- Run installers / MAX as administrator (this is running from the local admin account)

- Checked that NI-VISA appears under software in MAX

- Repaired MAX/NI-VISA

Is there anything else that could cause the COM ports not to appear in MAX when they appear (and work correctly) in device manager when a reinstall of NI VISA / MAX won't solve?

[Sam_Sharp · Accepted solution]

I found the solution - it turns out that the serial ports were available to LabVIEW, they just didn't show up in MAX because installing just the runtime does not show the devices in MAX.

Despite doing a lot of googling earlier, it didn't throw up this knowledgebase article until I searched for it under a different phrase - http://digital.ni.com/public.nsf/allkb/766FD80DAE42E52886256A0200619CFE?OpenDocument

[TOLGAHAN_NI]

My colleague checks more than 300 Arduino cards for troubleshooting if there is USB communication problem or not. At the end of the day, COM port name showed up like COM219 at device manager but at LabVIEW it did not show up as COM source. I reinstall everything but it did not help. Finally, I uninstalled the device which is showed up as COM219 and scan for hardware changes. At the end of this, COM port is changed to COM4. I tried again and it worked. It is obvious there is some limitation for selection COM port for LabVIEW, be careful if it reaches more than 200.

[billko]

It probably has to do with this KB article.