Trimble Outdoors r7 Manuale Utente

1 1       Event Marker Input and 1PPS Output

1 0 0      Trimble R7/R8 GPS Receiver User Guide

The Trimble R7 receiver can accept event marker input on Port 1 and 
Port 2, and can generate 1PPS output on Port 2.

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 V DC and 2.0 V DC 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 Trimble R7 records each event in the current data file. This record 
includes the port on which the event was received.

To enable or configure the event marker input function, you need the 
GPS Configurator software.

You can use GPS Configurator to configure a Trimble GPS receiver 
connected to your office computer. For more information, see GPS 
Configurator Software, page 70, or refer to the GPS Configurator 
Help.

To enable event marker input:

1.

Connect the computer to the Trimble R7 receiver.

2.

Press p to turn on the receiver.