+ AA6YQ comments below
On Mon, May 28, 2018 at 03:57 pm, James Wolf wrote:
I should have mentioned that the radio is an IC-7610.
+ The IC-7610 includes a built-in FSK interface. Unfortunately, Icom forgot to include an "Operating RTTY" section in chapter 4 of the IC-7610 Instruction Manual.
+ When you connect your IC-7610 to your PC with a standard USB A-B cable, two virtual serial ports are created. The lower-numbered virtual port is to be used (by Commander) for transceiver control. The higher-numbered virtual port can be configured for FSK Mark/Space switching via the DTR or RTS modem control signals; this is controlled by the "USB Keying (RTTY)" menu item on page 8-6 of the IC-7610 Instruction Manual. EXTFSK should be configured to use the appropriate modem control signal on the higher-numbered virtual port.