Configuring the NMEAMASK bitmask

The M7 GPS transponders and the Atlas PL personal locators may be configured to output NMEA 0183 GPS messages from its internal GPS receiver.  For GPS tracking, these GPS transponders can receive GPS position reports from other radios, and they may also be configured to output their own GPS location via their serial port.

Following is a list of the NMEA messages that are available (as of revision C2 of the Firmware).

NMEA Message
Bit Number (zero based)
Bit Mask (hex format / Decimal)
GGA 0 0x001  /  1
GLL 1 0x002  /  2
RMC 9 0x100  /  256

Refer to the product’s technical manual to see which NMEA messages are sent out in the various operating modes.  Once you set the “GPS Mode” of the radio using the GPS X command, you can change the NMEAMASK parameter to modify with of the NMEA sentences will come out the serial port.

For example, to have only the RMC sentence come out the serial port, use the following command”


To have the GGA and GLL come out the serial port use this command:


The NMEAMASK parameter is the sum of all of the decimal values of the individual bits corresponding to the NMEA messages.