| 摘要 |
PURPOSE:To specify a call from an undesired subscriber securely during a hot line period by comparing time set in a temporary hot line memory with current time and letting other subscribers know whether a hot line is set or not. CONSTITUTION:In a storage device MM, pieces of subscriber information and time information corresponding to subscribers are set, and a timer information comparing circuit TM1 which compares each piece of time information with current information is provided. A central controller CC sets a hot line between two subscribers on the basis of pieces of time setting information on both subscribers set in the storage device MM. The comparing circuit TM1 compares set information in the storage circuit MM with current time to decide on whether the current time coincides with the set time or not. Consequently, if a third subscriber calls one subscriber, e.g. A while the hot line is set between the subscribers A and B, a busy-back tone is sent out to specify incoming. |
