NMEA specification

Overview

Reach RS3 supports streaming of the following NMEA messages:

Message ID	Description
GGA	Time, position and fix type data
GSA	GPS receiver operating mode, satellites used in the position solution, and DOP values
GST	Position error statistics
GSV	Number of satellites in view, ID numbers, elevation, azimuth, & SNR values
RMC	Position, velocity, and time
VTG	Course and speed information relative to the ground
ZDA	UTC day, month, and year, and local time zone offset
EBP*	RTK base position
ETC*	Tilt compensation data

*This is a custom Emlid NMEA message. Learn more in the sections below.

By default, Reach RS3 outputs all the messages with the GN talker ID at the following frequences:

Message ID	Default talker ID	Default frequency
GGA	GN	5 Hz
GSA	GN	1 Hz
GST	GN	1 Hz
GSV	GN	1 Hz
RMC	GN	1 Hz
VTG	GN	1 Hz
ZDA	GN	1 Hz
EBP	GN	1 Hz
ETC	GN	5 Hz

You can change the default settings when setting up position streaming in the Emlid Flow app or in Reach Panel which can be accessed directly from Emlid Flow or in the browser on your PC. There you can change the talker ID from GN to GP, select the required set of messages, and change the frequency for all of them except for the ETC message. The GP talker ID is used for GPS measurements only and is usually required for integration with some third-party devices, such as agriculture and farming equipment.

note

When setting up NMEA messages, you may need to change the NMEA output rate, note that it should be equal to or lower than the GNSS update rate.

tip

Learn more about Reach Panel and access to it in the How to access Reach Panel from a web browser guide.

Emlid Base Position (EBP) message

EBP is a custom Emlid NMEA message that contains RTK base position.

Data contained

The message contains the following data:

Data contained	Representation
Talker ID and message prefix	$GNEBP
Latitude in degrees and decimal minutes	ddmm.mmmmmmm
Direction of latitude	N or S
Longitude in degrees and decimal minutes, should contain three digits of ddd	dddmm.mmmmmmm
Direction of longitude	E or W
Altitude above ellipsoid in meters	Float
Units of measurement for altitude	M
The checksum data	Starts with *, hexadecimal, two-digit number

Example

Here is an example of the EBP message Reach RS3 outputs:$GNEBP,4807.038,N,01131.000,E,545.440,M*58

Emlid Tilt Compensation (ETC) message

ETC is a custom Emlid NMEA message that contains tilt compensation data.

Data contained

The message contains the following data:

Data contained	Representation
Time of FIX in UTC	hhmmss.ss
State	Integer, "" : off 0 : fatal error 10 : setup 20 : alignment 30 : compensating
Notification	Integer, "" : tilt is off 0   : none 10 : fast motion 20 : bad gnss 30 : filter fault
Heading in degrees	Float, within the range [0.0, 360.0]
Tilt direction in degrees	Float, within the range [0.0, 360.0], value only provided in compensating state
Tilt value in degrees	Float, within the range [0.0, 180.0], value only provided in compensating state
n-axis accuracy coefficient	Float , value only provided in compensating state
e-axis accuracy coefficient	Float, value only provided in compensating state
u-axis accuracy coefficient	Float, value only provided in compensating state
Checksum	Starts with *, hexadecimal, two-digit number

Example

Here are examples of the ETC message Reach RS3 outputs:

• $GNETC,,,,,,,,,*7E: Tilt is off, no GNSS solution
• $GNETC,193828.80,,,,,,,,*6D : Tilt is off, GNSS solution is available
• $GNETC,193828.80,10,00,,,,,,*3B : Tilt is on, waiting for setup...
• $GNETC,193828.80,20,00,,,,,,*5A : Alignment. Move the receiver to calibrate tilt compensation.
• $GNETC,193828.80,30,00,172.543,5.621,2.344,1.013,0.993,1.021*4C: Compensating. The compensation data is ready to be used.
• $GNETC,193828.80,30,10,172.543,5.621,2.344,1.013,0.993,1.021*2H : Compensating. The compensation data is available, but there's a warning that the receiver may be moving too fast.

For developers

For more detailed information on the ETC message, download the PDF below.

Doc revision	Message revision	Size	Download link
Rev. 3	Rev. 1	260 KB	ETC_rev_3.pdf