| 摘要 |
PURPOSE:To prevent an urgent call, calls from important persons, and so on from being impeded, by making it possible to acquire a specific trunk in the same trunk group only from a specific extension subscriber when the traffic intensity becomes high in the PBX. CONSTITUTION:When all central office trunks NO.0COT-NO.NCOT become busy, the HTF relay is operated. In this case, since NO.0COT is designated as a reserved trunk, the htf' break contact and the trunk selecting circuit of NO.0COT are cut off by the operation of the HTF relay. When a specific extension subscriber dials the trunk line originating number under this state, the CLS relay and the OG relay are operated to select NO.0COT. Consequently, after the operation of the HTF relay, NO.0COT is reserved only for the specific extension subscriber immediately after the service of NO.0COT. |
