| 摘要 |
PURPOSE:To reduce the increase of call processing load of a common control device and software caused by error scanning information generated from a faulty calling line by constituting such that a line scanning information sending gate is closed to stop sending of line scanning information if the number of calling in certain time exceeds the threshold. CONSTITUTION:The subscriber's calling information (the loop of a subscriber's line 1) which has been detected in a subscriber's line interface 3 connected to the subscriber's line 1 is sent to a central processing unit 14 through the line scanning information sending gate 10 and makes the count-up of a calling number integrating counter 5 simultaneously. The calling number integrating counter 5 is reset to zero by a reset pulse which is supplied periodically from a periodical reset circuit 6. When an abnormal calling status detection circuit 7 detects the fact that the output of the calling number integrating counter 5 exceeds the predefined threshold, it outputs a line scanning information sending prohibit signal 9 to close the line scanning information sending gate 10 and to cause an alarm sending circuit 8 to send an alarm of abnormal calling status. |
