| 摘要 |
PURPOSE:To improve operability by providing a changeover switch, which is turned on or off to switch connection of a switching circuit, on the front of a transmission equipment and switching the connection from an internal circuit to a test terminal by the changeover switch. CONSTITUTION:Normally, a changeover switch 101 is turned off to connect contacts of switching circuits 103 and 106 to contacts B when the equipment is used. The PCM primary-group signal inputted to an equipment main body 1 through a transmission line 3 is converted to a unipolar signal by a signal converting circuit 102 and is inputted to a demultiplexing circuit 104 through the switch 103. The demultiplexing circuit 104 demultiplexes the input signal and outputs it to another equipment through a transmission line 4 as a 64kbps PCM signal. When a tester is connected to a test terminal 100 to monitor the PCM signal, the changeover switch 101 is turned on to connect contacts of switching circuits 103 and 106 to contacts B. Thus, the signal can be monitored because internal circuits 102, 104, 105, and 107 are connected to the test terminal 100. |
