Digital multiplexing system remote scanning of a plurality of monitoring points
First Claim
1. In a multiplexed data transmission system for transmitting data over a transmission line from a first location to a second location, sender means at said first location including first means for generating a serial pulse train including a start pulse followed by a plurality of data pulses during each of a plurality of time frames, second means for transmitting pulse trains provided by said first means to said second location over said transmission line, and inhibit means for inhibiting the transmission of pulse trains during alternate time frames, and receiver means at said second location including means for receiving said pulse train, data storage means, and sequencing means including clock pulse generating means responsive to the start pulse to provide a plurality of clock pulses having a predetermined relation to said start pulse for enabling said data pulses to be gated into said data storage means.
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Accused Products
Abstract
A digital start-stop multiplexing system including a sender which sequentially scans a plurality of monitoring points and generates a train of digital pulses coded to represent information provided at the monitoring points for transmission over a transmission line to a receiver which is responsive to the digital pulses to automatically synchronize itself with the sender, store the data pulses and provide indications of conditions indicated at the monitoring points. The receiver also monitors the transmission line and detects and displays open or short circuit conditions of the transmission line. Coded pulses may also be transmitted from the receiver location to the remote sender over the same transmission line during stop portions of the primary signal.
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Citations
24 Claims
- 1. In a multiplexed data transmission system for transmitting data over a transmission line from a first location to a second location, sender means at said first location including first means for generating a serial pulse train including a start pulse followed by a plurality of data pulses during each of a plurality of time frames, second means for transmitting pulse trains provided by said first means to said second location over said transmission line, and inhibit means for inhibiting the transmission of pulse trains during alternate time frames, and receiver means at said second location including means for receiving said pulse train, data storage means, and sequencing means including clock pulse generating means responsive to the start pulse to provide a plurality of clock pulses having a predetermined relation to said start pulse for enabling said data pulses to be gated into said data storage means.
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9. In a multiplexed data transmission system for transmitting data over a transmission line from a first location to a second location, sender means at said first location including means for generating a serial pulse train including a start pulse followed by a plurality of data pulses during each of a plurality of time frames, and means for transmitting the pulse trains provided during at least certain ones of said time frames to said second location over said transmission line, and receiver means at said second location including means for receiving said pulse train, data storage means including serial-to-parallel converter means and pulse storage means providing a separate storage location for each of the data pulses of a given frame, and sequencing means including clock pulse generating means responsive to the leading edge of the start pulse to provide a plurality of clock pulses having a predetermined relation to said start pulse, and means responsive to said clock pulses to provide shift pulses for enabling said data pulses to be shifted into said converter means, and means enabled after all of the data pulses of a given frame have been shifted into said converter means to provide a transfer pulse for enabling said data pulses to be transferred to said pulse storage means.
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13. In a multiplexed data transmission system for permitting the transmission of data over a transmission line from a monitoring location to a location remote from the monitoring location, sender means at said monitoring location including means for generating a serial pulse train including a start pulse and a plurality of data pulses each of which represents a normal or off-normal condition for a different one of a plurality of monitoring points, and means for transmitting said pulse train to said monitoring location over said transmission line, receiver means at said monitoring location including input means for receiving said serial pulse train, serial-to-parallel converter means, clock pulse generating means responsive to said start pulse for generating a plurality of clock pulses having a predetermined relation to said start pulse for synchronizing the operation of said receiver means, sequencing means responsive to said clock pulses to provide shift pulses for gating said data pulses into said converter means, and data storage means, said sequencing means including means responsive to a predetermined number of said clock pulses indicating that all of the data pulses of a given pulse train have been gated into the converter means to effect the transfer of said data pulses from said converter means to said data storage means.
- 17. In a multiplexed data transmission system for transmitting data representing the conditions of a plurality of monitoring points over a transmission line from a monitoring location to a location remote from the monitoring location, sender means at said monitoring location including point sensing means for providing a plurality of outputs each representing a noraml or off-normal condition for a different one of the monitoring points, sequencing means for effecting sequential readout of the outputs of the point sensing means to provide a serial pulse train including a start pulse followed by a plurality of data pulses each of which is coded to represent the condition of a different one of said monitoring points, and switching means controlled by said pulse train to enable the transmission of said start pulse and said data pulses over said transmission line to said remote location, and receiver means at said remote location including pulse detecting means for receiving said serial pulse train, data storage means, and clock pulse generating means responsive to said start pulse for generating a plurality of clock pulses having a predetermined relation to said start pulse for effecting the gating of said data pulses into said storage means.
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24. In a multiplexed data transmission system for transmitting data over a transmission line between first and second locations interconnected by said transmission line, sender means at said first location for generating a serial pulse train including a start pulse followed by a plurality of data pulses coded to represent the data to be transmitted, for transmission to said second location over said transmission line, receiver means at said second location including clock pulse generating means, and start pulse sensing means responsive to the start pulse of said pulse train to enable said clock pulse generating means to provide a plurality of clock pulses at a rate approximately twice the rate of said data pulses whereby a first clock pulse is provided at the leading edge of each data pulse and a second clock pulse is provided at the midpoint of each data pulse, shift register means and counter means for counting said clock pulses and for providing shift pulses to said shift register means for enabling each of the data pulses to be gated into said shift register means at the mid point of the data pulse, and a plurality of data storage means having a separate data storage location for each data pulse of said pulse train, said counter means being operable to provide a transfer pulse after all of said data pulses have been gated into said shift register means to effect the transfer of said data pulses from said shift register means to said data storage means.
Specification