Asynchronous digital TDM multiplexer-demultiplexer combination

摘要

An asynchronous digital TDM multiplexer-demultiplexer combination at one communication terminal is capable of multiplexing N asynchronous input data signals having a random mixture of different bit rates into a transmitted synchronous data stream having a predetermined fixed data format and a given bit rate greater than the sum of the rates of the different rates and to demultiplex N asynchronous output data signals having the same random mixture of the different bit rates from a received synchronous data stream having the data format and the given bit rate, where N is an integer greater than 1. Each of the N channel printed circuit board plug-in receptacles, coupled to a different one of the N input data signals and a different one of N outputs each for a different one of the N output data signals, has plugged therein a selected one of no printed circuit boards, a digital data channel printed circuit board and an FSK channel printed circuit board to process a mixture of digital data signals, teletype signals and FSK signals in the N input data signals and the received data stream, with the mixture of signals being in any random order and mix and the digital channel printed circuit boards and the FSK channel printed circuit boards being plugged in the N receptacles in any random order and mix. The multiplexing and demultiplexing frame synchronization and automatic channel assignment is controlled by a programmable common controller so that the data bits of each of the N input data signals are distributed throughout the time slots of the transmitted and received data stream with equal spacing.