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 4 of Lemo PORT 4.

Trimble P/N 36451-02 can be used as breakout box for the 1PPS output and Event marker input.