| 摘要 |
<p>The PBX has switching systems which divide the selectors (line finders and line selectors) of the internal connecting set, or equivalent equipment, in and individual part (AS) and in a central part. The call can be made in the individual or central part. The call can be made in the individual or central part, with subsequent engagement of the central or individual part. When the called subscriber answers, only an individual selector switches through the connection to both subscribers, so that when a starter and a finder switch are engaged, a central or individual selector is connected to it. Acoustic signals are transmitted through the connecting wires, and a call and a retransmission is carried out through the line selector part. When the called subscriber answers, switching means become operative and transmit the marked position of the central selector to the individual selector, with corresponding second setting of the market selector in the central part.</p> |
