| 摘要 |
PURPOSE:To detect the alarm through one transmission line and to hold the urgency of an alarm by transmitting a pulse for a fault to each panel from a monitoring device, and sending an alarm signal, added with the address of each panel to the pulse, when the panel has a fault. CONSTITUTION:From the clock pulse generator 32 of an alarm monitoring device 31, a clock pulse having an added frame synchronizing signal is transmitted to panels 36-1 and 36-2 through one alarm transmission line 35. The rise of this pulse is detected by the frame synchronism detectors 39 of the panels 36-1 and 36-2 to clear the contents of counters 38. Then, each counter 38 counts the pulse and applies the resulting signal to an AND gate 39 inputting an alarm state to control an analog switch 40 by the output of the gate 39, returning an alarm signal with an added address through the transmission line 35. This signal and the count value of the clock pulse are compared mutually by an alarm signal detector 33 to detect the alarm signal sources of the panels 36-1 and 36-2. |
