| 摘要 |
PURPOSE:To enable an extension speaker to be called from the host machine by installing a call switch in the host machine to make a ringing tone generating circuit operate for calls from both host and subsidiary machine. CONSTITUTION:If a call switch 20 installed in a subsidiary machine 2 is set on, ringing tones are generated from the speaker installed in a hand set 15 and the extension speaker 3 installed differently. If a call switch 8 installed in the host machine 1 is set on in the state that the hand set 15 is taken up, ringing tones are generated from both the speaker. Therefore, for example, when the subsidiary machine 2 is set outside as an entrance, the host machine 1 is set in a room on the first floor, and the extension speaker 3 is set in a room on the second floor, the host machine can responses to a calling from the subsidiary machine then call the extension speaker 3. |
