Data transmission system
First Claim
1. A data transmission system comprising a plurality of transmitters, a communication channel, and a receiver arranged to receive data transmitted from the individual transmitters sequentially over said communication channel, each said transmitter comprising:
- first timing means which, during periods when it is enabled, is arranged to time a first time interval, the first timing means being further arranged to generate an output signal upon completion of the timing of said first interval,a channel signal detector coupled to said communication channel and arranged to generate an output signal in the absence of a signal or noise on said channel,control means connected to said signal detector and said first timing means and responsive to the presence of the signal-detector output signal to enable the first timing means only during the absence of detected signal or noise on said channel,signal transmission means coupled to said communication channel and operative in response to the generation of a said output signal by the first timing means to transmit a data message of predetermined duration in signal form over said channel to said receiver, andinhibit means which, following the transmission of a said data message by said signal transmission means, is operative to prevent said transmission means from transmitting a further said data message over said channel for a second time interval the duration of which is sufficient to allow the other said transmitters to sequentially transmit their associated data messages, said inhibit means including second timing means for timing said second time interval,the duration of said first time intervals differing for each said transmitter by random delays whereby upon initial operation of the system, the transmitters will transmit in a sequence randomly established by the relative duration of their said first intervals, and therefor this sequence is maintained.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for the transmission of data from a number of out-station transmitters to a central receiver over a communication line or channel in which each out-station transmitter has an associated timer and a detector which "listens" to the line or channel and enables the transmitter only in the absence of detected signals from the other transmitters on the line or channel. When enabled each transmitter transmits data over the line or channel under control of its associated timer for a time interval during which the other transmitters are inhibited. The time intervals commence from the start times which differ from each other by different random delays which are short compared with the timed intervals, so that upon initial switching on of the system one of the transmitters will always commence transmission, followed by all the other transmitters in sequence.
18 Citations
5 Claims
-
1. A data transmission system comprising a plurality of transmitters, a communication channel, and a receiver arranged to receive data transmitted from the individual transmitters sequentially over said communication channel, each said transmitter comprising:
-
first timing means which, during periods when it is enabled, is arranged to time a first time interval, the first timing means being further arranged to generate an output signal upon completion of the timing of said first interval, a channel signal detector coupled to said communication channel and arranged to generate an output signal in the absence of a signal or noise on said channel, control means connected to said signal detector and said first timing means and responsive to the presence of the signal-detector output signal to enable the first timing means only during the absence of detected signal or noise on said channel, signal transmission means coupled to said communication channel and operative in response to the generation of a said output signal by the first timing means to transmit a data message of predetermined duration in signal form over said channel to said receiver, and inhibit means which, following the transmission of a said data message by said signal transmission means, is operative to prevent said transmission means from transmitting a further said data message over said channel for a second time interval the duration of which is sufficient to allow the other said transmitters to sequentially transmit their associated data messages, said inhibit means including second timing means for timing said second time interval, the duration of said first time intervals differing for each said transmitter by random delays whereby upon initial operation of the system, the transmitters will transmit in a sequence randomly established by the relative duration of their said first intervals, and therefor this sequence is maintained. - View Dependent Claims (2, 3, 4, 5)
-
Specification