ETL600
3.6.6.
3.6.6.1.
General ............................................................................................3-66
3.6.6.2.
Transmission time ............................................................................3-66
3.6.6.2.1.
3.6.6.2.2.
3.6.6.3.
Security ............................................................................................3-68
3.6.6.4.
Dependability ...................................................................................3-69
3.6.7.
Operating principle ...........................................................................3-71
3.6.8.
3.6.8.1.
General ............................................................................................3-72
3.6.8.2.
Speech bandwidth............................................................................3-73
3.6.8.3.
Guard signal.....................................................................................3-73
3.6.8.4.
Command signals ............................................................................3-74
3.6.8.4.1.
Dual-tone principle ...........................................................................3-74
3.6.8.4.2.
Trip frequencies ...............................................................................3-75
3.6.8.4.3.
3.6.8.5.
Boosting ...........................................................................................3-76
3.6.8.6.
3.6.8.6.1.
General ............................................................................................3-77
3.6.8.6.2.
3.6.8.6.3.
3.6.8.6.4.
3.6.8.6.5.
3.6.8.6.6.
3.6.8.6.7.
3.6.8.7.
Start Inputs.......................................................................................3-80
3.6.8.8.
Unblocking .......................................................................................3-80
3.6.8.9.
3.6.8.10.
3.6.8.11.
Rx Guard Signaling ..........................................................................3-82
3.6.8.12.
Blocking of AGC...............................................................................3-82
3.6.8.13.
Cyclic Loop Test...............................................................................3-82
3.6.8.14.
Manual Loop Test ............................................................................3-84
3.6.8.15.
Local Test Mode...............................................................................3-84
3.6.8.16.
Command Counters .........................................................................3-84
3.6.8.17.
Alarms Sources................................................................................3-85
3.6.8.18.
3.6.8.19.
3.6.8.20.
3.6.8.21.
3.7.
Event Recorder...............................................................................3-87
3.7.1.
General ............................................................................................3-87
3.7.2.
3.7.3.
3.7.4.
Upload events ..................................................................................3-89
3.7.5.
Upload counters ...............................................................................3-90
3.7.6.
Reset counter...................................................................................3-90
3.7.7.
Set clock...........................................................................................3-90
3.7.8.
3.7.9.
Views................................................................................................3-91
Contents
1KHW001489-EN
November 2005
ABB Switzerland Ltd
III