(Revision, 24 January 2002)

The automatic control system aiming at autonomous operation is drafted to be based on the GT 2000 terminal from GeoTec. The terminal will be connected to the tractor functions using CAN bus to an electronic control unit (ECU) or job computer, ESX from Sensor-Technik Wiedemann. The actuators and sensors will be connected to the ESX job computer.

The system will have three (major) operational modes:

1. Off: This mode is characterized by no power to the electronic control system, except for the GT 2000 and the GPS system. The ESX may be constantly powered according to the document ESX_HILFE and the power switching performed using the power control input D+ (0 Volt by Off mode).
   
2. Remote: The system (mainly steering, CVT and engine rpm) is functioning in remote control mode. The actuator control inputs are potentiometers and switches in a box (control panel) and are connected to an electric switch by cable. The ESX outputs are kept in the state corresponding to switching to mode Automatic. (It is assumed that later the ESX will perform simulation reporting to the RS 232 monitoring output which the controls to the outputs would have been if in mode Automatic).
   
3. Automatic: The control system is functioning for autonomous operation. In this mode the actuator control inputs are switched to the ESX outputs by relays.