NMEA specification
Overview
Reach RS2/RS2+ 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 |
*This is a custom Emlid NMEA message. Learn more in the sections below.
By default, Reach RS2/RS2+ 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 | G* | 1 Hz |
GST | GN | 1 Hz |
GSV | G* | 1 Hz |
RMC | GN | 1 Hz |
VTG | GN | 1 Hz |
ZDA | GN | 1 Hz |
EBP | GN | 1 Hz |
*Reach RS2/RS2+ outputs GSA and GSV messages with the successive talker IDs-GP, GL, GA, GB.
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.
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.
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