Patent Document ID: 3978449
Application ID: 05544207

Base Claim:
1. In a data communications system, apparatus for transmitting digital data and control signals on a common channel intermixed without restriction as to the format of data transmitted comprising; a multi-stage bit generator for generating a train of bits having a repeating sequence; means for combining data to be transmitted with the output of said bit generator to modify said data as a function of said bit sequence; a control code detector for detecting a predetermined number of bit combinations indicative of control information; means for applying the output of said combining means to the input of said control code detector; means responsive to the detection of a control code in said output for modifying said output; and means for selectively introducing control codes and the output of said last means into a transmission channel.

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Claim 3:
3. The combination in accordance with claim 1 wherein said apparatus includes means for converting all control words into different bit sequences, all preceded by an identical preamble and said control code detector is responsive to the detector of the said preamble of said control codes.