Canon fax basic 2000 서비스 매뉴얼

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BASIC OF TELEPHONE

2.5

Dial

Dialling enables an exchange to connect one party to a requested number

according to a dialing signal. “DP” means the Dial pulse contact. The con-

tact is usually closed. When you turn a dial and release it, the contact

opens the same number of times as the number you dialed. (When the

dialed number is 0, the contact opens 10 times.)

When a DC loop is made as shown in the Fig. 1-11 and the dial returns to

its start position after the number “4” is dialed, the DC loop is cut four

times. This is called the “dial pulse”.

Dialing using this dial pulse is called “pulse dial” due to the fact that num-

bers are dialed by this pulse.

Fig. 1-11 Dial Pulse

The exchange selects and calls up the other party by counting the number

of dial pulses.

Dials return to their start position at either of two speeds:

• 10PPS

• 20PPS

PPS (Pulse Per Second) indicates how many dial pulses are generated per

second.

T: Transmitter

R: Receiver

DP: Dial pulse contact

HS (Off-hook state)

HS: Hook switch

OFF

9 0

Dial return

OFF