Dell 2135cn Service Manual page 807

Pulse Dialing & Tone Dialing
Pulse dialing
"3, 5, ...... "
Switch
Tone dialing
"3, 5, 2, ...... "
Switch
3) The switch connects lines according to the transmitted number.
4) When a connection between local switches is established, the local switch of the called party
sends a ringing signal to the telephone of the called party. The telephone that receives the ringing
signal emits its ringtone. At the same time, the called party's local switch sends a ring back tone
(RBT) to the calling party's telephone to indicate that a connection to the called party has been
established.
Version 1 2008.02.01
3
3
DTMF matrix
1209Hz 1336Hz 1447Hz
High frequency
Chapter 6 Principle of Operation (Fax)
5 .........
2 .........
5
697Hz
770Hz
852Hz
941Hz
6 – 8
Low
frequency
Gnb06025KA