Command Signals; Dual-Tone Principle - ABB ETL600 Instruction Manual

ABB Switzerland Ltd
Speech 2000 Hz
Speech 2200 Hz
Speech 2400 Hz
Speech 3400 Hz
NSD600 Guardfilter
Fig. 3-40
Speech 2000 Hz
Speech 2200 Hz
Speech 2400 Hz
Speech 3400 Hz
Fig. 3-41
If two TPE are configured, one in the APLC and one in the DPLC
channel, a band of 500 Hz is always reserved in the DPLC channel for
the guard of TPE2. The trip frequencies of TPE2 are located in the
DPLC channel just like in a standard APLC channel of 4 kHz (at the
upper or at the lower end of the DPLC channel, depending whether it
is configured as "erected" or "inverted"; refer to section 3.1.1 for
details).
3.6.8.4.

Command signals

3.6.8.4.1.

Dual-tone principle

Protection commands are transmitted by the NSD600 using "dual
tone" tripping signals, i.e. two (tripping) frequencies simultaneously
sent - each having half the amplitude of a corresponding single tone
3-74
1KHW001489-EN
ETL: useful AF bandwidth
2320 Hz
2120 Hz
Examples for allocation of the 4 kHz band with speech
and the ETL600 pilot as NSD600 guard signal
ETL: useful AF bandwidth
Guard
Examples for allocation of the 4 kHz band with speech
and an own NSD600 guard signal
November 2005
Teleoperation Ch.
Teleoperation Ch.
Teleop. Ch.
2520 Hz
Teleoperation Ch.
Teleop. Ch.
Guard
Teleop. Ch.
Guard
2680 Hz
2480 Hz 2880 Hz
Structure and Function
ETL600
Pilot
Pilot
Pilot
Pilot
3600 Hz
3840 Hz
Pilot
Pilot
Pilot
Pilot
3720 Hz
3840 Hz