| 摘要 |
PURPOSE:To ensure the effective monitor for the coding unit of the pulse code modulation communication unit by inserting the monitor pulse into the common wiring and then giving the comparison between the state on the common wiring and that in the multiple signal. CONSTITUTION:In case the monitoring is given to the encoder or the decoder of the coding unit, the synchronous pulse is supplied to common wiring A from synchronous pulse input terminal 15 via insersion circuit 14 and then supplied to exclusive logic sum circuit 20 via common part 12 of the transmitter side. Then the comparison is given at circuit 20 between the original synchronous pulse and the synchronous pulse sent from part 12. And in case no coincidence is obtained through the comparison owing to occurrence of the fault at wiring A, the output of circuit 20 becomes ''1''. And the output of output terminal 18 shows ''1'', and the monitor signal is delivered. In the same way, the front and back state of the pulse at common part 13 are compared with each other at exclusive logic sum circuit 21 at the receiver side via the PCM signal sent from PCM input terminal 8. In this way, the encoding unit in the pulse code modulation communication unit can be monitored effectively. |
