| 摘要 |
PURPOSE: To separate faults in a complicated communication network, such as a collision detection network. CONSTITUTION: A loop back plug 300 has a small enclosure and is connected to a DTE through an AUI interface. A connector 321 has contacts for a signal that passes through the plug. The enclosure is provided with a relay 322 that is operated by a mode switch, which sets an outbound control signal from the DTE. When the relay 322 is located at a 1st position, both inbound and outbound data signals are connected, and a medium access unit is simulated during a normal data transmission. When it is set at a 2nd position by an outbound control signal, it tests the continuity of an outbound control line and a network interface power source line, in addition to testing collision by sending an inbound control signal. |
