Troubleshooting and Repair
85
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Table 11: A-B Bit Signalling Example (T1/CO)
State
Transmit
Receive
A
B
A
B
Outgoing call - Basic Operation
Idle state
0
1
1
*
PBX grounds ring (wait for dial tone)
0
0
1
*
CO ground tip (dial tone applied)
0
0
0
*
PBX closes loop and removes ring ground
1
1
0
*
Dial pulsing
DP
1
0
*
Completion of dialing
1
1
0
*
Incoming call - Basic Operation
Idle state
0
1
1
*
CO ground tip (interval between ringing)
0
1
0
1
CO ground tip (during ringing application)
0
1
0
0
PBX presents call
0
1
0
1
PBX answers call
1
1
0
*
Talking state
1
1
0
*
CO disconnects
Talking state
1
1
0
*
CO removes tip ground (far end hangs up)
1
1
1
*
PBX opens loop (idle)
0
1
1
*
PBX disconnects
Talking state
1
1
0
*
PBX opens loop (near end hangs up)
0
1
0
*
CO removes tip ground (idle)
0
1
1
*
Summary of Contents for SX-200 EL
Page 1: ...TECHNICIAN S HANDBOOK LIGHTWARE 19 RELEASE 3 0 ...
Page 11: ...Chapter 1 Introduction ...
Page 12: ......
Page 32: ...Technician s Handbook 22 ...
Page 33: ...Chapter 2 Routine Maintenance ...
Page 34: ......
Page 55: ...Chapter 3 Troubleshooting and Repair ...
Page 56: ...Technician s Handbook 46 ...
Page 88: ...Technician s Handbook 78 Figure 16 E M Trunk Type I 2 wire ...
Page 110: ...Technician s Handbook 100 ...
Page 111: ...Chapter 4 Programming ...
Page 112: ......
Page 168: ...Technician s Handbook 158 ...
Page 169: ...Chapter 5 Installation ...
Page 170: ......
Page 239: ...Chapter 6 Maintenance Commands ...
Page 240: ......
Page 258: ...Technician s Handbook 248 ...
Page 261: ...Notes ...
Page 262: ...Technician s Handbook Notes ...