NMEA-0183 messages: Overview

Applicable receivers:  All receivers

When NMEA-0183 output is enabled, a subset of NMEA-0183 messages can be output to external instruments and equipment connected to the receiver serial ports. These NMEA-0183 messages let external devices use selected data collected or computed by the GNSS receiver.

All messages conform to the NMEA-0183 version 3.01 format. All begin with $ and end with a carriage return and a line feed. Data fields follow comma (,) delimiters and are variable in length. Null fields still follow comma (,) delimiters, but contain no information.

An asterisk (*) delimiter and checksum value follow the last field of data contained in an NMEA-0183 message. The checksum is the 8-bit exclusive of all characters in the message, including the commas between fields, but not including the $ and asterisk delimiters. The hexadecimal result is converted to two ASCII characters (0–9, A–F). The most significant character appears first.

The following table summarizes the set of NMEA messages supported by the receiver.

Message	Function
ADV	Position and satellite information for RTK network operations
DP	Dynamic positioning
DTM	Datum reference information
GBS	GNSS satellite fault detection (RAIM support)
GGA	Time, position, and fix related data
GLL	Position data: position fix, time of position fix, and status
GNS	GNS Fix data
GRS	GRS range residuals
GSA	GPS DOP and active satellites
GST	Position error statistics
GSV	Number of SVs in view, PRN, elevation, azimuth, and SNR
HDT	Heading from True North
LLQ	Leica local position and quality
MSS	MSK receiver signal
PASHR	RT300 proprietary roll and pitch sentence
PASHR,PBN	Position and velocity information
PFUGDP	A proprietary message containing information about the type of positioning system, position, number of satellites and position statistics
PTNL,AVR	Time, yaw, tilt, range, mode, PDOP, and number of SVs for Moving Baseline RTK
PTNL,BPQ	Base station position and position quality indicator
PTNL,DG	L-band corrections and beacon signal strength and related information
PTNL,GGK	Time, position, position type, and DOP values
PTNL,PJK	Time, position, position type, and DOP values
PTNL,PJT	Projection type
PTNL,VGK	Time, locator vector, type, and DOP values
PTNL,VHD	Heading Information
RMC	Position, Velocity, and Time
ROT	Rate of turn
VTG	Actual track made good and speed over ground
ZDA	UTC day, month, and year, and local time zone offset

To enable or disable the output of individual NMEA messages, do one of the following:

• In the receiver web interface, select I/O Configuration. Choose the required port to output NMEA messages. Select NMEA as the output message type and then enable or disable individual NMEA messages as required.

• Create an application file in the Configuration Toolbox software that contains NMEA output settings and then send the file to the receiver.

For detailed information about these messages, please refer to the OEM GNSS receiver help at www.trimble.com/OEM_ReceiverHelp/.

For a copy of the NMEA-0183 Standard, go to the National Marine Electronics Association website at www.nmea.org.