Computer/bus message system for vehicle drive control system

A drive system for a utility vehicle, the drive system comprising:

• a generator driven by an internal combustion engine;
• at least one drive axle with wheels;
• at least one steerable axle with wheels;
• a plurality of actuator systems, including individual electric drive motors for driving the wheels of the drive axle and powered by the generator, and steering actuators for steering the wheels of the steerable axle;
• a plurality of manually operable input control devices, including a steering input control device and a speed input control device;
• a plurality of controllers, including steering controllers for controlling the steering actuators and motor controllers for controlling the electric drive motors;
• a process computer having a plurality of parallel and substantially independently operating function modules which receive input signals from the input control devices and which generate control signals which are supplied to the plurality of controllers;
• and
• a system bus communicated with the process computer and with the plurality of controllers, the process computer generating a control message which is communicated over the bus simultaneously to all of the plurality of controllers, and the process computer generating other signals which are communicated between the function modules without being communicated over the bus.