User Manual

10 Event Marker Input and 1PPS Output
110 5700/5800 GPS Receiver User Guide
55700 Reference
10.1Introduction
The 5700 receiver can accept event marker input on Port 1 and Port 2,
and can generate 1PPS output on Port 2.
10.2Event Marker Input
Event marker input is used to log a precise GPS time tag whenever an
externally generated pulse, such as one generated at the time of the
shutter closing from a photogrammetric camera, is received.
The event is triggered when the source pulse voltage transitions
between 1.0 VDC and 2.0 VDC in less than 100 nsec. Trimble
recommends that you use TTL level inputs. 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 5700 receiver records each event in the current data file. This
record includes the port on which the event was received.
10.2.1 Enabling and Configuring Event Marker Input
To enable or configure the event marker input function, you need
either GPS Configurator or Configuration Toolbox.
In real time
You can use GPS Configurator to configure a Trimble GPS receiver
connected to your office computer. For more information, see GPS
Configurator Software, page 78, or refer to the GPS Configurator
Help.
To enable event marker input:
1. Connect the computer to the 5700 receiver.
2. Press  to power on the 5700 receiver.