| 摘要 |
PURPOSE:To make it possible to know previously whether absence transfer of a call is performed or not before a called subscriber answers, by supplying various ringings to a calling subscriber depending upon discrimination between an absence transfer call or others. CONSTITUTION:Dialing telephone number 2XX of SUBB for a call from SUBA causes idle register OR to start maker MKR. Then, MKR actuates number group frame NGF and also actuates a relay in NGF corresponding to 2XX received from OR as well. When an ABSK relay is previously put ino operation so as to transfer the call to SUBB to SUBC, an extension line equipment relay of MKR operates corresponding to 3XX. At this time, an ABM relay of NGF also operates. On the other hand, MKR actuates intra-office trank IOT acquisition relay F. An ABMA relay of IOT operates by earthing of NGF to send IR out to SUBC of 3XX and also to send SRBT to the tertiary winding of a D relay at the same time, besides SRBT to SUBA. |
