Custom Configuration of a Vehicle Electrical Control System for Production and Service 2001-01-2791
International Truck Engineering has incorporated a cab electrical system controller (ESC) into their vehicle design. This was done to facilitate a larger number of configurations with a simpler hardware design. The ESC makes use of SAE J1939 and J1708 to communicate with instrument cluster, door, power train and other modules. It also has various discrete inputs and outputs. A proprietary operating program written for the ESC uses a set of binary configuration structures stored in flash ROM and includes a proprietary “byte code” interpreter. The configuration describes how to process all I/O signals to/from a central data array, byte code to execute and the instrument cluster layout. Byte code operates on the data array between input and output processing. The switches and gauges in the instrument cluster plug into network modules.
Due to the variability of the International Truck & Engine vehicle products, the content of the ESC configuration can vary widely from vehicle to vehicle. It is the IT (Information Technology) organization's task to provide a specific configuration for each ESC. Based on customer ordered features, the configuration must contain the proper byte code modules, I/O processing and cluster configuration information. IT must also select the proper switches, gauges and warning lights and their locations, as well as match the discrete I/O to signals on pre-existing wiring harnesses. The software and hardware included in the configuration must be validated to prevent software and hardware conflicts.
In addition to the initial configuration, IT must also provide vehicle service support. This includes reconfiguration of the ESC for software updates, recall support and customer driven additions or modifications. The system that IT developed to solve these issues is discussed.