Trimble Outdoors AgGPS 332 - Manual (Page 102)

C NMEA-0183 Messages
9 2 AgGPS 332 GPS Receiver User Guide
11 Direction of magnetic variation
E: Easterly variation from True course (subtracts from True
course)
W: Westerly variation from True course (adds to True course)
12 Mode indication
A: Autonomous
D: Differential
N: Data not valid
Table C.11 RMC message fields (continued)
Field Description