| 摘要 |
<p>PURPOSE:To increase the using efficiency of the call control means and thus enhance the economical performance, by installing the call control means of the multiparty subscriber telephone to the device which is shared by plural numbers of the multiparty subscriber line. CONSTITUTION:Only the applying means of the DC high voltage for display of the originating ready state of party line subscriber telephones PS1-PSn, the dial tone detecting means and the like are provided to party line subscriber adding device PLA installed to each multiparty subscriber line PL, thus simplifying the constitution. On the other hand, the call control means of telephones PS1-PSn which require a complicated constitution such as the called number information and various types of information storing circuits, the aural frequency oscillator, call signal sending/stopping circuit and the like are provided concentrically to party line subscriber's intra-office trunk PIOT which is shared by multiplarty subscriber lines PL. Thus this connecting system is more economical then the system in which the call control means is provided to the party line trunk installed to each line PL.</p> |
