Hardware - Geometrics Forum https://www.geometrics.com/community/g-858-hardware/ Geometrics Discussion Board en-US Wed, 15 Apr 2026 23:32:12 +0000 wpForo 60 How can I connect a GPS to my G-858 Magnetometer? https://www.geometrics.com/community/g-858-hardware/how-can-i-connect-a-gps-to-my-g-858-magnetometer/ Wed, 09 Aug 2023 21:40:33 +0000 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. Be sure to set the RS232 protocol to 9600 Baud, 8 Databits, 1 Stop Bit and No Parity.

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.

]]> Hardware Gretchen Schmauder https://www.geometrics.com/community/g-858-hardware/how-can-i-connect-a-gps-to-my-g-858-magnetometer/