Electrical device command system, single wire bus and smart single controller arrangement therefor

摘要

A multiplex system for addressing, commanding and monitoring the status of a plurality of electrical devices disposed throughout a motor vehicle. A dual-duty cycle type voltage waveform generated by a microcomputer provides address signals for enabling individual controllers connected to a bi-directional single wire bus coupled at one end to a driver and receiver circuit of the microcomputer. After the individual controller is addressed, another portion of the waveform provides information for operating the electrical device in response to a polarity control data bit portion of the same voltage signal to turn the connected element either ON or OFF. Circuits within the addressed controller provides current signal indicative of the ON or OFF statues of the electrical device.