| 摘要 |
PURPOSE: A loop back device and the method are provided to perform a point-to-point control loop back, even though a subscriber signal is not delivered. CONSTITUTION: A loop back device using a random pattern in an N 64KBPS high speed data network comprises: a random pattern generator(1) for generating an X6+X4+1 random pattern; an inversion section(2) for outputting and selecting the random pattern as a loop back request signal or a loop back release signal, by control of a loop back selection signal; a data selection section(3) for selecting and transmitting one of signals outputted from the inversion section and main data, by the control of the data selection signal; a serial/parallel data storage circuit(4) for storing the data from the data selection section(3), by converting the data in serial; a loop back observing section(5) for examining whether the X6+X4+1 loop back pattern is correct from the stored data; a loop back release observing section(6) for observing the loop back release signal; a loop back latching section(7) which a loop back request is latched and maintained, when the loop back request signal is entered for regular time; a loop back performing section(8) for performing a loop back function; a same data observing section(9) for preventing an error of the loop back pattern; and a control clock section(10) for generating/controlling a clock necessary for a system from a reception clock.
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