Rugged reliable 30.000 foot solid state altitude encoder. with virtually no warm up time the SSD-120-30A-RS232C Altitude encoders with Serial Altitude Output provide standard "Grey Code" to the aircraft's mode C transponder, and two RS232 altitude data outputs with 10 foot resolution for use by GPS and Terrain Awareness Systems (TAWS). Each RS232 output is totally independent and can be programmed to transmit two different protocols at two different baud rates simultaneously.