The DF9IC digital connector standard is very widespread in Europe. Its layout provides optimum signal separation as each signal line in the ribbon cable is separated from the others by a least one other ground line. Using jumpers, most lines can be connected directly or set to zero for test purposes. The following diagram shows the connector pinout on the modem side. It also shows audio output connector used on some of the USCC cards. The connector used is a male DIL connector with 2*10 pins and 2.54mm pin spacing.
All signals have TTL levels. Signals marked with a bar are active low.
All BayCom USCC cards use the DF9IC connector as their modem interface.
