What is the expected format of the CAT commands for PTT? I tried TX;ff,fe,88,00,1c,00,01,fd RX;ff,fe,88,00,1c,00,00,fd I also tried prefacing 0x in front of the hex values, also delimiting with semicolon. I watched the com port communications and VarAC just sends the same ASCII string as configured out the com port, not the hex/binary. -for Icom 7100