2.3 | GNSS Receiver & IMU Compatibility
Compatible GNSS Receivers
The requirements below outline the important components and considerations for using a GNSS receiver with Level COMMAND.
- StarFire RTK, NMEA 0183 Fixed RTK over RS232 serial, or NMEA 2000 Fixed RTK output over ISOBUS/CANBUS.
- Suitable adapters are available to connect RS232 or CANBUS and 12V external power to the COMMAND harnessing system.
- Ruggedised and suitable for earthmoving machine control applications.
Receivers being used with COMMAND must be capable of RTK positioning calculations. Differential GPS or SF signals are NOT considered suitable for vertical position feedback as position accuracy and repeatability is too low.
John Deere StarFireTM
COMMAND is able to interface with all modern StarFire receivers over ISOBUS/CANBUS for position feedback, including StarFire 3000, 6000, 7000 & 7500 models.
NMEA 2000
COMMAND is able to interface with with GNSS receivers supporting NMEA 2000 standard output over ISOBUS/CANBUS for position feedback such as modern Case Vector Pro, New Holland PLM Cygnus & Trimble NAV 900 receivers.
Supported NMEA 2000 ISOBUS/CANBUS PGNs
- 129029 - GNSS Position Data
- 129539 - GNSS DOPs
- 129025 - Position, Rapid Update
- 129026 - COG & SOG, Rapid Update
- 129028 - Altitude Delta, Rapid Update
NMEA 0183 (Serial) - RS232
COMMAND is able to interface with any receiver capable of providing NMEA 0183 standard sentences over RS232 serial for position feedback. The sentences below are required at a minimum for usage with Level COMMAND.
Required NMEA 0183 Sentences
- GGA - Time, position, and fix related data
- GSA - GPS DOP and active satellites
- VTG - Actual track made good and speed over ground
Optional NMEA 0183 Sentences
- RMC - Position, Velocity, and Time
- ZDA - UTC day, month, and year, and local time zone offset
NMEA 0183 Sentence Rate
A minimum message rate of 5 Hz is required, with 10 Hz recommended.
RS232 Baud Rate
The RS232 baud rate can be selected in Level COMMAND as 19200, 38400, 57600, and 115200 bps. A baud rate of 38400 is recommended.
Compatible Cross-slope / Roll / Tilt Sensors
For users making use of X-Slope control using the COMMAND ECU's second output function, we recommend the use of the T3H-E003 COMMAND Inclination Sensor – TARS-B to ensure that the angle sensor being used is robust and accurate for automatic implement control.
StarFireTM TCM (Terrain Compensation Module)
COMMAND can make use of the in-built StarFire TCM, which provides feedback on pitch and roll angle of the receiver. The Starfire TCM can be selected as a X-Slope / Tilt sensor but we cannot guarantee the accuracy / bias drift of the sensor and generally recommend the use of T3H-E003 shown below.
T3H-E003 - COMMAND Inclination Sensor – TARS-B
A TARS-B inertial measurement unit configured by T3RRA can be used to provide reliable feedback on the pitch and roll angle of the implement and can be mounted on the scraper for automatic X-Slope control when using non-JD receivers such as Case IH Vector Pro or Trimble NAV 900.
