| 摘要 |
PURPOSE:To enable to calculate the call fee automatically, even if no polarity inversion is obtained, by starting the calculation of call fee through an off-hook output, in an automatic dial device having the call fee calculating function. CONSTITUTION:After the transmission of a dial signal, when an opposing subscriber picks up a handset of a telephone set 15, a control section 2 starts the calculation of call fee through the reception of an off-hook detection output of a hook detection circuit 14 and displayed on a display device 6. When the call is finished and the handset of the telephone set 15 is hooked off, the hook detection circuit 14 detects it and informs it to the control section 2. If the polarity of the power supply of a station is inversed through the response of called party, the control section 2 once resets the call fee calculation started with the off-hook detection and the fee calculation is started from the point of time again. Thus, the calculation of call fee is made even for a private branch of exchanger which is impossible for the inversion of polarity. |
