How can I have two LabVIEW exes share a COM port?

[DMcAndrew]

Does anyone know how to let two executables share one VISA COM port? (I don't want to build them into the same application.)

Thank you,

Dave

[Makoto]

If your environment is Win32, the system does not allow multiple processes to open the same COM port at a time.  The solution is one of the followings:

(1)Avoid to open the com port at a time.  For example, the first app must close the com port before the second app tries to open it.

(2)Create a separate process that acts as the com-port-access proxy or server.  Your two apps must communicate with the com port through the server process instead of direct access, by using one of IPC (inter process communication) mechanisms.

[Makoto]

As a similar approach of (2) I said above, I found a ready-made software - Serial Splitter.

http://www.serial-port-communication.com/split-comport/

This software looks like virtualize multiple com ports being mapped to a single physical port, using Win NT kernel drivers.