G-858 Cesium Magnetometer FAQ

1. How can I connect a GPS to my G-858 Magnetometer?

It is a fairly simple task to connect a GPS to a G-858 magnetometer. You can use the External I/O cable assembly and a null modem to connect the G-858 to most GPS receivers.

Null modems are available from Geometrics or from local Radio Shack or computer stores. The Null modem pin configuration for GPS receivers that have a data cable compatible with 9 pin IBM PC COM ports has male pins on both sides.

The GPS should be set to output NMEA data that contains the $GPGGA sentence.

The G-858 must have its serial port set to the same baud rate as the GPS.

You can use System Setup->Com & Field Note String Setup->Chat Mode to determine whether correct communications have been established.