Synchronisation of a radio telemetry system

摘要

A control telemetry device transmits a periodic synchronisation signal to remove telemetry devices to establish synchronisation. The time period between successive synchronisation transmissions is divided into a series of message specific time slots eg. for remote stations to transmit data or alarm signals to the control device thus avoiding transmission clashes caused by simultaneous transmission of data between the remote devices and the control device. Each device comprises a microcomputer 1, a clock 2, and a radio transmitter 8 and a receiver 9 each connectable to an antenna 10 via a switch 11 controlled by the microcomputer 1. The microcomputer of a remote device receives data from telemetry sensors via data-in lines 21 and sends signals to another device, such as an alarm, via data-out lines 22. The device may save power by the clock 'waking up' the microcomputer only for the duration of the synchronisation signal and for transmissions.