ABB ETL600, Instruction Manual

Page: 108 / 382

ABB Switzerland Ltd
1KHW001489-EN ETL600
3.6.8.4.3. Command assignment to trip frequencies
Input Signal F1 F2 F3 F4 F5 F6 F7
A x x
B x x
AB x x
C x x
AC x x
BC x x
ABC x x
D x x
AD x x
BD x x
CD x x
ABD x x
ACD x x
BCD x x
ABCD x x
Test x x
Not used x x
Not used x x
Not used x x
Not used x x
Not used x x
Table 3-5 Command assignment to trip frequencies
3.6.8.5. Boosting
Signal boosting in connection with a PLC channel means that the
power used for transmitting tripping signals is stepped up in relation to
the quiescent state (i.e. the guard signal).
During the transmission of tripping signals, the communication of the
DPLC as well as the communication of speech, teleoperation channels
(set as 'disconnectable') and modem signals superimposed on the
speech in all channels is switched off (this includes the pilot signals in
APLC channels without TPE). The total transmitter power is available
now for the tripping signals. This ensures the best possible signal-to-
noise ratio at the receiving NSD600. The ratio between the powers of
the boosted transfer tripping signals and the guard signal is referred to
as the
boost ratio
and is normally expressed in decibel (dB).
The boost ratio which can be achieved depends on what other PLC
signals can be switched off while tripping signals are being
transmitted. This in turn is dependent on just how many signals the
ETL600 has to handle and for this reason, the boost ratio is calculated
automatically by the HMI600 after configuring the equipment.
3-76 November 2005 Structure and Function