One COM port, two applications

Is there a way to have two applications that need the PTT COM port to run simultaneously, maybe via virtual COM ports? I.e. VARA FM and UZ7HO Soundmodem for AX.25 Packet.
It works with RA-Board/RB RIM, just wondering if it’s possible with DigiRig.

Martin AJ6OH

Virtual COM port splitter may be an option, but I haven’t received positive confirmation of this scenario. Please keep us posted if you decide to give it a try.

Maybe. I have a convoluted mess of audio cables, interfaces, radios, etc that would be hard to describe. I am running Winlink Express and UZ7HO Easyterm on the computer. VHF packet is on one radio and Hf packet is on the other radio. HF rig uses COM port for PTT and VHF radio uses a separate VOX actuated interface such as a Signalink USB. By selecting dual PTT in UZ7HO Soundmodem, the audio going to the HF rig miraculously does not key up the VHF even though it is VOX actuated.
Now I know that VOX is usually bad news for digital ops, but it works for me on VHF packet. My situation is not exactly yours, but I am running two apps on one computer. The key to my mess is using both channels (left and right audio) of UZ7HO Soundmodem, and having mutiple radios and interfaces.
Maybe you could build audio cables to isolate left and right channels and run two Digirigs, or run two soundcards, etc.
Anyway I hope to improve my chaotic situation, but maybe there is an idea for you to work with here.


You might try a free program called com0com. I use it to allow my IC-7300, Win4Icom and N3FJP ACL share the same USB com port. So I have CAT control of the 7300 and all settings are displayed on Win4Icom, and ACL will pull data for logging. The Win4Icom site has information of the program and some others.

Hope this helps

Randy KA0AZS


As far as I understand, (… and I’m not very far along the path), once the COM port is being used, it is unaccessible to another app.

Thanks all who chimed in.

My goal is to limit it to one soundcard interface (DigiRig in this case) since it’s in a man pack configuration with a Yaesu FTM-6000 and a Mini-PC, with UZ7HO Soundmodem and VARA FM.
I have a different, non-DigiRig, configuration for the Gateway at my QTH.

I’d tried com0com, but I couldn’t get it configured properly. Maybe it’s because it generates COM port pairs, rather than splitting one?

I’m currently trying out VSPE (Virtual Serial Port Emulator), and it seems to work as far as I can tell. I’ll have to see how it performs.

Martin AJ6OH

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