Repeater for transmission system for controlling and determining the

Abstract

A repeater for use in a two way communication system for retransmitting information between a first device and a second device to help ensure reliable two way communication between the devices, comprising: a transmitter/receiver, the transmitter/receiver receiving signals from the first and second devices and transmitting the received signals for reception by the respective first and second devices; and further wherein a direct communication path for the information between the first and second devices is provided, the direct communication path being intermittently unreliable, the repeater providing an additional path for the information between the first and second devices; the repeater being spaced from said first and second devices by a specified distance, said specified distance being significantly less than a theoretical maximum communication distance thereby to ensure communication reliability. A plurality of repeaters can be provided in the system as the overall system expands when additional first and second devices, such as master units and control devices, are added. The plural repeaters employ a repeater transmission sequence in order to ensure reliability of communication. In addition, the repeaters build a bit map of status information received during the repeater sequence to ensure that all status information is received by each master unit.