| 摘要 |
<p>PURPOSE:To simplify the connection test by devising the transmitter-receiver such that a sender side sends a test signal and an acknowledge signal used for a receiver side to inform the reception of the test signal to the sender side and the receiver side returns the acknowledge signal to the sender side when the receiver side detects the test signal. CONSTITUTION:When a test command is given to a test side transmission circuit 11, a test signal generating circuit 15 sends the test signal to an insertion circuit 12. The circuit 12 inserts the test signal to a part of a frame format (Ff) of an input main signal from the circuit 11 not in use and sends the resulting signal to a connection line. A reception circuit 21 to be tested uses test signal detection and discrimination circuits 25, 27 to detect and discriminate the test signal on the Ff of the main signal thereby making acknowledge of the test signal reception and allowing an acknowledge signal generating circuit 14 of the circuit 11 to generate the acknowledge signal. The circuit 21 uses an acknowledge signal detection circuit 26, the circuit 27 to detect and discriminate the reception of the acknowledge signal on the Ff from the circuit 11 and returns the acknowledge signal reception notice to the circuit 11. Thus, the connection test for each connection line is simply executed.</p> |
