If you use a Trimble GPS Pathfinder Receiver (XR, XRS, Power or Pocket) as an external source of GPS data for the G1 data-collector (as opposed to using the G1’s internal GPS receiver), the G1 Serial Cable is required. It is used to connect the serial output cable of the Trimble unit, which terminates in a 9-pin female plug, to the G1’s right-hand (Com4) terminal.

The G1 Serial Cable has a 9-pin male plug on one end (which connects to the serial output cable from the Trimble unit) and a 26-Way Mini-D plug (male) on the other end (which connects to the G1).