| 摘要 |
<p>PURPOSE:To allow a center equipment to independently check the restoration of its own circuit by installing a circuit loop-back means to a supervisory control center equipment at the side of a supervisory control terminal equipment in terms of an information transfer line and looping back transmission/reception signals when a line between the center equipment and said equipment is witched to a pay station circuit. CONSTITUTION:A loop-back part 11 for exclusively used circuits 3 and 4 is installed at the side of the terminal equipment 2. When said circuits 3 and 4 develop troubles, a circuit connecting both lines is switched to the pay station circuits 5 and 6, and simultaneously the loop-back part 11 applies looping-back to the circuits 3 and 4. Namely a signal line 3 from the center equipment 1 and a signal line 4 to the center equipment 1 are directly connected by the loop-back part 11 and signal lines 12 and 13. Thus a signal transmitted from the center equipment 1 returns to the center equipment itself through the signal line 4 irrespective of the terminal equipment 2 of the supervisory controller, whereby the center 1 equipment alone can detect the restoration of the circuits 3 and 4.</p> |
