Multiplexed Operator Control Switches in a Modular Package 2001-01-2739
The increase in the number of electronics in Trucks, and the resultant increasing in wiring, has led to an inevitable emphasis on reducing wiring harness size and complexity. The use of Multiplexing allows the application of additional electronics without proportional increases in wiring. Multiplexing also adds the benefits of increasing the flexibility in electronics placement (modularity) and thereby reducing incorrect wiring. By utilizing the J1587/J1708 SAE standards in modular switches, these capabilities can be achieved, but with many challenges not normally seen in these traditionally simple devices.
The keys to acceptance are to keep the capabilities of present control switches, reduce the wiring complexity in manufacturing, provide flexibility for bodybuilders, and to gain the acceptance of truck operators. This paper is an overview for the architecture of one method to implement multiplexed control switches, discuss the hardware design challenges, and an overview of the software implementation necessary to provide modularity and bodybuilder flexibility.