Loop controller for a loop data communications system

Claim 1

In a time division multiplexed loop communications system having a plurality of data processors connected in series relation forming a loop, a loop controller connected in said loop and in series with said data processors, said loop controller comprising: means adapted for receiving and demodulating signals received from said loop; means couples to said receiving and demodulating means for extracting timing information signals from said signals received from said loop; timing means for providing transmit timing signals, synchronization signals and framing information signals; means responsive to said extracted timing information signals and to said transmit timing signals for retiming said demodulating signals with transmit signal timing information; a signal delay means for imparting an adjustable delay time to said retimed demodulating signals, said signal delay means comprising first and second shift registers, said first shift register being adapted to receive said retimed demodulated signals, said second shift register being adapted to receive marker signals at times corresponding to said first shift register receiving said retimed demodulating signals, said first shift register further being adapted to receive a spacer signal after receiving said retimed demodulated signals, said second shift register being adapted to receive a spacer indication signal at times corresponding to the receiving of a spacer signal by said first shift register, the delay provided by said signal delay means being related to the total number of spacer indication signals stored in said second shift register; a frame comparison means for comparing framing information from the signals provided by said delay means with the framing information signals from said timing means and for providing a search signal to said delay means based on the results of said comprison; means for coupling said search signal to said signal delay means; means for altering the total number of said spacer indication signals in said second shift register in response to said search signal for adjusting the delay time provided by said signal delay means; means for multiplexing the delayed signals from said delay means with said framing and synchronization signals from said timing means; and means for modulating said multiplexed signals in accordance with a particular modulation rule and for transmitting said modulated signals on said loop.