1PPS and ASCII time tag

The receiver can output a 1 pulse-per-second (1PPS) time strobe and an associated time tag message. The time tags are output on a user-selected port.

The leading edge of the pulse coincides with the beginning of each UTC second. The pulse is driven between nominal levels of 0.0 V and 5.0 V (see the following figure). The leading edge is positive, rising from 0 V to 5 V.

The pulse is about 8 microseconds wide, with rise and fall times of about 100 nsec. Resolution is approximately 40 nsec, but the following antenna cable length limits accuracy to approximately ±1 microsecond. Each meter of cable adds a delay of about 2 nsec to satellite signals, and a corresponding delay in the 1PPS pulse.

1PPS is available on pin 20 on the back connector of the receiver. If you have applications that require 1PPS, Trimble recommends that you use cable P/N 60789-00 or P/N 77070-00 because it has the following connectors:

  • D9 port for modem 1/serial 2.

  • D9 port for modem 2/serial 3. Pin 9 on this D9 port has 1PPS.

  • BNC connector for 1PPS.

  • Ethernet male plug for connection to receiver.

  • USB plug.

  • DC jack for supplying power to the receiver.