CONTROL SYSTEM USING TIME DIVISION MULTIPLEXING

摘要

CONTROL SYSTEM USING TIME DIVISION MULTIPLEXING A control system for selectively communicating a plurality of sensors with associated remote control devices includes a Master Synchronizer, a transmitter for each sensor and a receiver for each control device. A single signal line is connected to all transmitters and receivers, and a single synchronization line couples the Master Synchronizer to all transmitters and receivers. The Master Synchronizer generates a time frame signal which has a reset portion for resetting all transmitters and receivers synchronously at the start of each frame, and a periodic portion which determines the time slots for each frame and which decrements counters in all transmitters and receivers synchronously. A time division multiplex system is used to communicate each transmitter with one or more associated receivers during a predetermined time slot of a periodic time frame determined by the Master Synchronizer. At the beginning of each frame, all counters are set to a predetermined number representative of the time slot allocated to those units. When their counters are decremented to zero, a time slot is defined for communicating a transmitter with its associated receiver or receivers. Thus a transmitter is permitted to send a signal along the signal line which causes a response only in the receiver whose counter has been decremented to zero during the same time slot. A decrementing counter in the Master Synchronizer defines the complete time frame; and when it reaches zero, the transmission of sync pulses to all transmitters and receivers is inhibited for a predetermined time. This absence of sync pulses is used to reset the Master Synchronizer and all transmitters and receivers at the start of each frame. An energy-containing signal, rather than the absence of a signal, is required to activate a control device.