| 摘要 |
PURPOSE:To prevent malfunction of an abnormal supervisory device attended with initialization of an exchange by providing a means inhibiting an output of an abnormal signal until the initialization of the exchange is finished. CONSTITUTION:The abnormal supervisory device 4 is provided with a transformer 41 receiving a dial tone signal S1 from the exchange 1, a dial tone detection circuit 42 and a decision circuit 43 judging whether or not the signal detected by the detection circuit 42 is normal. An output of the decision circuit 43 is given to a set terminal S of an FF47 and a system start end signal SIPL from the exchange 1 is fed to a reset terminal R. Thus, the initialization of the exchange 1 is finished, no abnormal signal S4 from the FF47 is generated. Thus, malfunction of the abnormal supervisory device attended with the initialization of the exchange is prevented in this way. |
