I just received this radio from another ham and am hoping to get going on VarAC but struggling to get control working properly.
I have a RIGBlaster Plug & Play which seems to work fine in WSJT-X in all ways. I can use CAT control over CI-V, PTT is working, and audio is flowing into and out of the accessory port as expected.
Once I jump into VarAC, things fall apart. Firstly, there's no CAT control profile for the 756 non-Pro. You might think the 756 Pro would work, but it doesn't, at least not with the interface I own. I am able to successfully control PTT with DTR/RTS set to RTS on the proper COM port, but I can't use CAT control to set the frequency or mode. I've found I can use OmniRig to control the frequency successfully, but whenever OmniRig is connected to the appropriate COM port, I can no longer access the COM port with VarAC to make use of the RTS PTT. It says "Access to the port 'COM4' is denied." whenever I test the PTT in this condition. There are no options in OmniRig for exposing RTS as the PTT control. You can force it high, but it just stays high all the time.