2 | COMMAND System Overview
- 2.1 | System Architecture
- 2.2 | Supported Implement Types
- 2.3 | GNSS Receiver & IMU Compatibility
- 2.4 | Tractor / Electrohydraulic Compatibility
- 2.5 | Selecting System Components
2.1 | System Architecture
Theory of Operation
COMMAND is an electronic control system designed by T3RRA consisting of an Electronic Control Unit (ECU) along with a harnessing system to interface with different sensors, hydraulic and tractor systems.
Once installed and configured, the ECU acts as both a control system and interface. It will communicate with a PC running T3RRA software, the earthmoving implement and sensors providing real-time feedback on the position of the implement, and tractor diagnostic data where available.
Level COMMAND can then control the implement based on your current position and design elevation, while satisfying constraints e.g. cut depth limits.
Manual Control Mode
In Manual Control Mode, and also when the system arming switch is deactivated, COMMAND is Disengaged and any prescribed elevations sent to the ECU will not result in activation of hydraulics. Hydraulic outputs can still be activated using a connected joystick or tractor SCV levers. These will function regardless of whether COMMAND Automatic Control is Disengaged or Engaged.
Automatic Control Mode
Once the operator has Armed the system and Engaged Automatic Control Mode, the ECU activates hydraulic outputs based on:
- Prescribed elevation
- Current elevation
- Calibration parameters
- Tracking sensitivity
- Tracking/acquire thresholds
While Engaged, joystick movement can override automatic control. Depending on configuration, joystick movement can either Disengage Automatic Control Mode or Momentarily Disengage control until the joystick returns to centre.
2.2 | Supported Implement Types
COMMAND machine profiles are used to store all configuration settings for that particular implement including GNSS input selections, valve configuration, calibration and tuning values etc.
Implemented and Tested Machine Profiles
COMMAND currently has the following machine profiles available for selection on the ECU:
| Machine Profile | Controlled Functions | Example Usage |
| Single Scraper - Height | Function 1 - Height | A bucket scraper with single proportional height control valve and a single GNSS receiver |
| Single Scraper - Height & XSlope |
Function 1 - Height Function 2 - XSlope / Tilt |
A bucket scraper with a single proportional height and single proportional tilt control valve fitted with a single GNSS receiver and single inertial measurement unit (IMU) |
| Single Ditcher - Height | Function 1 - Height | A V-ditcher with a single proportional height control valve and a single GNSS receiver. |
Machine Profiles Currently In Testing
Machine profiles listed below are currently under development and may become available in future software releases.
| Machine Profile | Controlled Functions | Example Usage |
| Single Ditcher - Height & Pitch | Function 1 - Height Function 2 - Pitch |
A tile plow with a single proportional height, single proportional pitch control valve, single GNSS receiver and single inertial measurement unit (IMU).
|
| Tandem Scrapers - Height |
Function 1 - Height 1 Function 2 - Height 2
|
Two bucket scrapers in tandem, each with a single proportional height control valve and single GNSS receiver. |
| Single Scraper - Dual Height | Function 1 - Height | A bucket scraper with a single proportional height control valve but two GNSS receivers (One on the left of the implement, one on the right) |
| Single Scraper - Height (Dual Cylinder) | Function 1 - Height Left Function 2 - Height Right |
A bucket scraper with dual proportional height control valves (controlling left and right height separately), and two GNSS receivers (left and right). Maintains blade angle to allow manual X-Slope / Tilt operation. |
| Single Scraper - Height & XSlope (Dual Cylinder) | Function 1 - Height Left Function 2 - Height Right |
A bucket scraper with dual proportional height control valves (controlling left and right height separately), and two GNSS receivers (left and right). |
2.3 | GNSS Receiver & IMU Compatibility
The requirements below outline the important components and considerations for using a GNSS receiver with 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.
NMEA 2000 (CANBUS)
COMMAND is able to interface with GNSS receivers supporting NMEA 2000 standard output over ISOBUS/CANBUS for position feedback including but not limited to Case Vector Pro, New Holland PLM Cygnus & Trimble NAV 900/960 receivers.
Supported NMEA 2000 PGNs
- 129029 - GNSS Position Data
- 129539 - GNSS DOPs
- 129025 - Position, Rapid Update
- 129026 - COG & SOG, Rapid Update
- 129028 - Altitude Delta, Rapid Update
Position Update Rate
A minimum position update rate of 5 Hz is required. 10 Hz is recommended.
NMEA 0183 (RS232 Serial)
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 COMMAND.
Required Sentences
- GGA - Time, position, and fix related data
- GSA - GNSS DOP and active satellites
- VTG - Actual track made good and speed over ground
Optional Sentences
- RMC - Position, Velocity, and Time
- ZDA - UTC day, month, and year, and local time zone offset
Position Update Rate
A minimum message rate of 5 Hz is required. 10 Hz is recommended.
RS232 Baud Rate
The RS232 baud rate can be selected in COMMAND as 19200, 38400, 57600, and 115200 bps. A baud rate of 38400 is recommended.
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.
Differential GNSS or SF corrected signals e.g. SF3 are NOT considered suitable for implement position feedback as position accuracy and repeatability are insufficient.
Compatible Cross-slope / Roll / Tilt Sensors
For users making use of Cross-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.
T3H-E003 - COMMAND Inclination Sensor
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 Cross-slope control when using receivers such as Case IH Vector Pro or Trimble NAV 900.
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 Cross-slope / Tilt sensor but we cannot guarantee the accuracy / bias drift of the sensor and generally recommend the use of T3H-E003 shown above.
2.4 | Tractor / Electrohydraulic Compatibility
COMMAND can make use of either in-built rear tractor electrohydraulic valves, commonly referred to as SCVs (Selectable Control Valves) or auxiliary remotes, or externally mounted electrohydraulic valves.
For each valve type, COMMAND is able to provide two raise and lower functions for automatic control of function 1 (e.g. height) and function 2 (e.g. cross-slope / tilt). For CANBUS based valve types, any available SCVs/Remotes will be available for selection.
For proportional solenoid, Analog Voltage (0-5V) and Danfoss PVE types, the number of selectable outputs is limited to the number of available physical outputs on the ECU suitable for analog voltage laser inputs or external EH valves.
| Valve Interface | Description | Applicable Valve Adapter/s | Suitable example tractors/valves |
| JD CAN | COMMAND can communicate directly with John Deere SCVs over CANBUS, sending flow requests that will be enacted by the John Deere tractor hydraulic system. | N/A | Most modern John Deere tractors, e.g. 8R, 8RT, 9R, 9RT, 9RX. |
| J1939 | COMMAND can communicate directly with the T3RRA VM or other compatible hydraulic controllers using the J1939 messaging standard. | N/A | Challenger tracked machines |
| Fendt SCR/S4/MT | COMMAND can communicate directly with Fendt SCVs over CANBUS, sending flow requests that will be enacted by the tractor hydraulic system. |
Use T3H-V005 and S/111 valve adapters. |
Fendt SCR, S4 and MT models where the SCV control bus is separated from the ISOBUS. |
| Fendt ONE | COMMAND can communicate directly with Fendt SCVs over CANBUS, sending flow requests that will be enacted by the tractor hydraulic system. | Use T3H-V005 valve adapter. | Fendt Gen 7 / ONE tractor models |
| Analog Voltage (0-5V) | COMMAND can provide 0-5V analog voltage signals suitable for John Deere legacy proportional SCV controller or Case IH / New Holland 0-5V EHR controller inputs. | Use T3H-V001 valve adapter. | Case 0-5V EHR inputs or John Deere legacy proportional laser inputs. |
| Proportional Solenoid | COMMAND can provide closed-loop PWM signals suitable for controlling external proportional solenoid valves requiring maximum flow current of less than 2 Amps. | Use T3H-V002 and T3H-V003 valve adapters. | Scraper systems using external proportional solenoid valves such as Eaton Vickers, Rexroth or Hydac. |
| Danfoss PVE | COMMAND can provide 0-Vs ratiometric voltage signals as well as power supply suitable for controlling external Danfoss PVEM, PVEA, PVEH and PVES valves. |
Use T3H-V002 and one of T3H-V006 or T3H-V007 valve adapters. |
Scraper systems using external closed-loop proportional valves such as Danfoss PVEM, PVEA, PVEH or PVES. |
2.5 | Selecting System Components
Correct component selection is important for reliable installation and operation of the COMMAND system. Harnessing requirements will vary depending on tractor model, implement configuration, GNSS receiver type, and hydraulic interface. For assistance selecting compatible components, use the COMMAND kit picker at t3rra.com or contact T3RRA.
Factors that will affect harnessing requirements include:
- Tractor brand
- Tractor model
- Scraper brand
- Scraper model
- GNSS receiver model
- Available Electrohydraulic Valves
Harnessing Compatibility
The COMMAND harnessing system has been designed to allow us to leverage existing customer and dealer knowledge of tractor and implement harnessing systems. We can then take advantage of this familiarity on the technical support front, while leveraging the fact that dealers also possess many of these parts in stock at-the-ready.
Typical CNH Components
| SKU / Part No. | Name |
|
115-0172-397 OR 115-0172-398 OPTIONAL POWER |
Constant Power Harness (Row Crop) OR Constant Power Harness (Articulated) |
|
115-7100-009 OR 115-7100-010 REQUIRED |
Front Extension Wiring Harness Kit |
|
115-7100-005 REQUIRED |
Cable Adapter Terminator Gen I ISOBUS |
|
92179218 OR 92317566 REQUIRED IF NO ISO IBBC PRESENT |
Row Crop Tractor ISO Connector OR Articulated Tractor ISO Connector |
Typical John Deere Components
| SKU / Part No. | Name |
|
BPF10403 OR BPF10404 OPTIONAL |
Constant Power Harness (Row Crop) OR Constant Power Harness (Articulated) |
|
BPF11117 REQUIRED |
Front Extension Wiring Harness Kit (including terminator module) |
|
RE174725 OR RE174726 REQUIRED IF NO ISOBUS PRESENT |
GreenStar™ Ready Field Installation Kit (Rowcrop) OR GreenStar™ ISO Implement Connector Field Installation Kit (Articulated) |
|
BPF12658 REQUIRED IF USING STARFIRE GNSS |
Implement Receiver Wiring Harness Kit |
|
BPF10547 RECOMMENDED |
iGrade Counterbalance Valve kit - highly recommended if the implement has no existing counterbalance mechanism |
Base COMMAND Components
The components below are required for a base COMMAND installation.
| SKU / Part No. | Name |
| T3H-E001 | COMMAND ECU – Controller Only |
| T3H-L001 | COMMAND ECU Licence – Licence Only |
| T3H-C002-1 | COMMAND ECU Adapter - CAN & Analog V2 |
| T3H-C003 | COMMAND Arm/Engage Switch Adapter |
| T3H-C004 | COMMAND Arm/Engage Switch |
| T3H-C005 | COMMAND ISOBUS/Ext Breakout Adapter |
| T3H-C006 | COMMAND Cab Breakout Adapter |
| T3H-C008 | COMMAND Cab/Ext Extension Adapter |
| T3H-T001 |
Tablet Serial Interface Adapter (RA 4m) |
Optional COMMAND Components
Components listed below are optional for COMMAND and will only be required for certain tractor models, scraper models, GNSS receivers, Tilt sensors or Electrohydraulic valves.
| SKU / Part No. | Name |
| Tractor Harnessing | |
| T3H-F001 | Cab Convenience Power Adapter |
| T3H-F002 | External Loose End Power Adapter |
| T3H-F003 | COMMAND Inline Fuse Adapter |
| T3H-J001 | COMMAND Joystick Adapter – 4m Extension |
| T3H-M001 | COMMAND J1939 Diagnostic Adapter (Green) |
| T3H-T002 | Tablet Serial Interface Adapter (RA 6m) |
| T3H-V001 | COMMAND Legacy Analog Output Adapter |
| T3H-V002 | Valve Adapter – 6m Extension |
| T3H-V003 | Valve Adapter – Prop. Solenoid (2-way DT) |
| T3H-V005 | COMMAND Tractor CAN Valve Adapter |
| Implement Harnessing | |
| T3H-E003 | COMMAND Inclination Sensor – TARS-B |
| T3H-G001 | COMMAND NMEA Extension Harness (8m) |
| T3H-G002 | COMMAND Impl Adapter – NAV-900 / Ag372 |
| T3H-G003 | COMMAND Impl Adapter – Emlid Reach RS2/RS2+/RS3 |
| T3H-G004 | COMMAND Trimble NMEA Output Adapter |
| T3H-G007 | COMMAND NMEA Extension Harness (12m) |
| T3H-S001 |
COMMAND Impl Adapter – Stub Junction |
| T3H-S003 |
COMMAND Impl Adapter - TARS Extension |