A SWITCHING CONTROL APPARATUS USING V4 BYTE IN A SYNCHRONOUS MULTIPLEXER

摘要

PURPOSE: A switching control apparatus using a V4 byte in a synchronous multiplexer is provided to facilitate an operation, maintenance and repairing even without a TMN unit by displaying a switching command in a V4 byte and requesting a switching from a remote office. CONSTITUTION: In a system in which a local office is connected to a remote office through a channel so as to exchange a DS1 class data through the same synchronous multiplexer, and when an operator of the local office requests a remote loop-back from the remote office through a terminal, a multiplexing unit of the remote office makes a remote loop-back of a signal of a corresponding DS1 class, a TU12 transmitting unit(42) for transmitting a TU12 having pointers(V1,V2,V3,V4) added to VC12 includes the first latch(f_1) for receiving inf data carrying information and latching it according to a bit clock, the second latch(f_2) for receiving a V4 data with a switching command indicated and latching it according to a V4 clock; an AND gate(AND) for ANDing the bit clock and the V4 clock, the third latch(f_3) for receiving an output of the AND gate by its clock terminal and latching an output of the second latch(f_2), an exclusive OR gate(ex_or) for exclusively ORing an output of the first latch(f_1) and an output of the third latch(f_3), and the fourth latch(f_4) for latching an output of the exclusive OR gate(ex_or) according to the final bit clock.