| 摘要 |
A bidirectional data communications system having many remote terminals operating with a central unit includes means at each terminal for reproducing a clock from the incoming data. Upstream data from the terminals to the central unit is transmitted at the same frequency as the incoming data using the reproduced clock from the downstream transmission. At the central unit, the incoming data from each terminal is of arbitrary phase, but must be extracted without delay from the upstream transmission for data processing purposes. A clock signal substantially resynchronized with the data stream is provided by detecting the initial presence of data, and timing the frequency division of a higher frequency original clock so that the phase and frequency of the data match the clock requirements at the central unit.
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