The SSD120-(XX)N-RS1 Series Nano Altitude Encoders are all solid-state devices that measure air pressure and convert the measurements into the ICAO parallel data for pressure altitude transmission via ICAO pressure altitude Gray Code output. These Nano encoders also provide altitude data to ADS-B, GPS, transponders, autopilots, and other navigational devices with two asynchronous RS232 and one RS-485 outputs for which the serial data protocol can be individually selected. The user has multiple resolution settings to choose from. Typically, the altitude data is set to 100 feet or 10 feet. The RS1 version has one-foot resolution available on the second RS-232 output only.