Scanning known serial ports for a specific response

[lumonic]

I need to build a test fixture for a device that uses a Silicon Labs Dual CP2105 chipset that talks to two different sections of the board to be tested. Since it's USB it will be somewhat random which port enumerates as what when a new DUT gets put in place. 

I have a VI that can identify the ports, attached below. I need to take the resulting serial ports found and send an ASCII "??" to them. If in the first line of the response contains  "FPGA" that means I have found the right port and I will want to be using that for the rest of my communications. 

And idea how to do this? Serial communication is new to me for labview. 

[mcduff]

You would need to cycle through each port.

1. Open each port.
2. Set Serial settings, baud rate, parity, etc.
3. Query with ??.
4. Look at response.

See below:

The above can be improved, just a sketch of what is possible.

mcduff

[Eric1977]

I had a similar project that I had to enumerate through the serial ports as well as enumerate through each of the BAUD settings.

Doing what mcduff provided is exactly what I did to achieve my goal.

[lumonic]

Thanks! That pushed me in the right direction. Attached what I ended up with. 

[Eric1977]

You can eliminate that first For Loop. It's not needed since your using aliases.

[mcduff · Accepted solution]

Here's a one loop suggestion to try. (I assume you only have one FPGA port attached, otherwise then make an array and get rid of the conditional stop.)

mcduff

[lumonic]

OK, that works.

Thanks!

[crossrulz]

I would also advise using the "expression" input on the Find VISA Resource.  With it, you can easily filter out all of the TCP and GPIB resources.  For my reuse, I also filter out the COM ports that I know are not what I am looking for (I know are used by other devices, were previously detected and looking for a new port due to USB connection, etc).

[find_a_new_alias]

oops, wrong login account of mine, see the next message

[Peter_B]

Does anyone else find that the VISA Find Resource function used

takes a long time (8 seconds for me) to execute ?   Even when the list is empty it still takes that long to excute which seems unusually long.

Peter