Magellan GPS 320 - Manual (Page 56)

48 Magellan GPS 315/GPS 320
Connecting to DGPS
To use the PC interface cable to interface the GPS receiver with the DBR-2 or
DBR-3, you must use a null modem (Radio Shack P/N: 26-264A) and a gender
changer (Radio Shack P/N: 26-280A) to connect the GPS receiver properly. This
is due to the pinout being the opposite of the DB9 connector configuration for a
PC connection.
For the DBR (differential beacon receiver) that has a DB9 connector on the
housing, the pinout is:
9
5 1
6
Pin 2: Data out to GPS
Pin 3: Data in
Pin 5: Sig. GND