Event marker input

Use event marker input to log a precise GNSS time tag whenever an externally generated pulse is received, such as one generated at the time of the shutter closing from a photogrammetric camera.

The event is triggered when the source pulse voltage transitions between 1.0 V DC and 2.0 V DC in less than 100 nsec. Trimble recommends that you use TTL level inputs, 0 - 5 V. You can configure the receiver to recognize either a positive (rising) or negative (falling) voltage as the leading edge of a pulse. The accuracy of the associated time tag recorded for an event is determined by the GPS accuracy (typically less than 1 μsec.).

The receiver records each event in the current data file. This record includes the port on which the event was received.

The maximum voltage on the event marker input is 6 V. Input impedance is 1 KΩ.

The Event Marker Input is available on pin 5 of Lemo PORT 4.

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