Xerox Phaser 6180MFP, Service Manual

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2-96 Phaser 6180MFP Multifunction Printer Service Manual
Theory of Operation
1. When the handset is lifted, the hook switch is activated and a
transmission signal (400Hz/48VDC), called a dial tone (DT), is sent from
the local switch. The dial tone is audible at the handset speaker, indicating
that the calling party can start dialing.
2. Entering the telephone number by rotating the dial or pushing the buttons
transmits the number to the local 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 orienting. 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.
5. When the called party’s handset is lifted, activating the hook switch, the
local switch on the called party side receives a response signal and stops
sending tones to the calling and called parties. This is when a
communications path is established between both parties.
s6180mfp-104
Connecting Out-of-Town Calls
a. Lift the Handset
b. Dial the Number
c. Calling
d. Line Established
1) Dial Tone
Calling Party Called Party
Local
Switch
Local
Switch
Tandem
Switch
Tandem
Switch
2) Phone
Number
3) Lines Are Automatically Connected.
Connection
Established
4) Ring Back Tone
4) Ringing
Signal
Hello
Hello
5) Response
Signal
Communications Path is Established.