DTMF-ENC232 is a DTMF (dual tone multiple frequency) encoder board that is controlled via 9600 baud RS-232 serial commands.  By using a terminal program such as HyperTerminal or custom developed software, an attached radio transmitter can be keyed with continuous or momentary DTMF digits being sent at any interval.  Example applications include the remote controlling of complicated repeater controllers and the driving of DTMF relay camera pan / tilt systems.