Pin # Signal Name Description 1 BATTERY Externally applied backup power ( + 5 V) 2 +5V PWR +5 V regulated main power 3 GROUND Ground (receiver) 4 VPP Flash memory programming voltage 5 RTCM IN RTCM input 6 1PPS One pulse per second signal 7 1PPS RTN One pulse per second return 8 TTL TXD Transmit 5V logic 9 TTL RXD Receive 5V logic 10 TTL RTN Transmit/receive return
