Find available COM ports

[slarve]

Hello

I have a labview program made by a colleague who has found a new job, but after changing production computer (win10 to win11) no COM ports are found.

The device is a Virtual Com Port and has an FTDI chip. FTDI chip drivers are installed. 

I see that it find the COM port but then it checks "SYSTEM\ControlSet001\Control\COM Name Arbiter\Devices" in the registry and there is nothing saved there. And it then returns -603.

I have found a fix by inverting the error and starting the labview program (inHouseTest.exe) in administrator mode. 

But why is this?

[crossrulz]

I would just use the VISA Find Resource and it will just return the available VISA resources.  You can apply a filter to the search to make it only the COM ports that show up.

[slarve]

Yeah I know.

But why did it work before on the old computer and have stopped working now? Both on the old and the new production computer. 

And it works on my computer but not on the production computers. 

I guess it has something to do with the registry SYSTEM\ControlSet001\Control\COM Name Arbiter\Devices beeing empty at the prooduction computers.

[paul_a_cardinale]

Microsoft has never been particularly concerned about compatibility.

[BertMcMahan]

Can you get to the COM port using a regular terminal program (like Termite or TeraTerm)?

It sounds like your FTDI drivers are not actually installed correctly, or perhaps you didn't get NI VISA installed correctly.

[slarve]

Yes i can open the COM port in realterm.

FTDI drivers are installed twice. (Did not find a way to remove them)

And have tried a repair of NI VISA.

[cordm]

Do you have another control set in the registry? Is SYSTEM\CurrentControlSet\Control\COM Name Arbiter\Devices also empty?

[slarve]

Yes, SYSTEM\CurrentControlSet\Control\COM Name Arbiter\Devices is also empty on my production computers.

[crossrulz]

I think you are best off just ignoring the registry.  Even Microsoft says you should avoid using it.  Just use the Find VISA Resource like I showed above and you will know what ports are available regardless of where things may be stored in the registry.

[slarve]

It works fine with my fix for one program but another labview program has some vi's lacking so I can't build it again. 

It's not used that often but would be nice to have that working as well.

That would probably involve editing the registry or installing some drivers.