| 摘要 |
PURPOSE:To improve the operability of a crossbar type exchange by detecting a prescribed operation done by a calling extension subscriber after a called subscriber gives an answer in an automatic outgoing mode of a main wire and therefore starting an extension transfer means. CONSTITUTION:An extension transfer adding device CBA is connected to a main wire outgoing truck OGT connected to a line link frame LLF of a crossbar type private exchange, and an extension transfer link CBL is connected to the device CBA. An extension subscriber A of the exchange is connected to an originating-only line OCL via the frame LLF and the truck OGT to set a main wire in a busy state. In this case, the device CBA detects an answer of a called subscriber. Then the subscriber A intends to transfer a main wire call to another extension subscriber B and carries out a prescribed operation. This fact is detected by the device CBA. Then the line OCL is held and connected to an extension transfer CBT via the link CBL. Thus the operability of the exchange is improved. |
