1.5 EQUIPMENT DESCRIPTION
1.5.1 CONTROL OFFICE EQUIPMENT
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| LAYOUT OF CONTROL OFFICE EQUIPMENT |
1) Digit Keys (0 -9) :- used for entering station codes.
2) Group Keys (A, B, C ,D, G) :- calling different groups ( G means all station ).
3) Cancel Key (DL) :- clear wrong entry.
4) Repeat Key (RT) :- redials last number.
5) Long Ring Key (LR) :- generates long key at way station.
6) Test Key (RC) :- used for testing equipment.
7) Reset Key (RS) :- resets COE.
1.5.1.1 TESTING OF CONTROL OFFICE EQUIPMENT
1) Test (RC) key is pressed. The equipment then goes to test mode.
2) A continuous DTMF tone corresponding to any of the DTMF frequencies is available at output.
3) Pressing RC switch repeatedly, the frequencies changes and corresponding row and column number appears at display.
1.5.1.2 DTMF FREQUENCIES
| ROW NO | FREQUENCY (IN HZ) | COLUMN NO | FREQUENCY (IN HZ) |
|---|---|---|---|
| 1 | 697 | 1 | 1209 |
| 2 | 770 | 2 | 1336 |
| 3 | 852 | 3 | 1477 |
| 4 | 941 | 4 | 1633 |
1.5.2 WAY STATION EQUIPMENT
Way station equipments consists of an PCB joined by telephone. Its basic layout is given below
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| WAY STATION EQUIPMENT PCB |
Way station PCB has following main parts. We will dig into its working later.
1) DIP switch 1 & 2 :- used to assign a station code to W.S.E station
2) Group DIP switch :- used to assign a group code to W.S.E station
3) Telephone Terminals :- used to connect W.S.E telephone to the W.S.E PCB
4) Line Terminals :- used to connect channel to the W.S.E PCB
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