| 摘要 |
PURPOSE:To avoid a telephone line from being closed by using a control means to control the number of times of call independently of a call number of time changeover switch when a call signal comes after a storage capacity of an incoming message memory circuit reaches the upper permissible limit. CONSTITUTION:The detection criterion for the number of times of call is updated by a control signal outputted only after a control circuit 9 detects the operating state of an incoming message memory circuit 15 and detects it that the storage capacity reaches the upper limit of the allowable range. A call number of time changeover switch 20 to switch the detection criterion of the number of times of call of a call number of time identification circuit 19 is subjected to detection criterion setting to allow the call number identification circuit 19 to give an output by 3-time call. A closing circuit 21 brought into the operating state by an output signal of the call number of time identification circuit 19 controls the switching of the closing switch 3.
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