ABB ETL600 Instruction Manual page 329

Revision:
A
Discarding a new equalizer: If after several measurements all new equalizers have worse results
than the actual equalizer, it is better to leave the old equalizer unchanged by quitting 'Select
equalizer' with the 'Cancel' button.
Activating a new equalizer: After finding a new equalizer suitable, select the new desired equalizer
in 'Equipment' / 'Commissioning and maintenance' / 'Select Equalizer' / 'APLC channel X'.
Then press the 'Download' button. A dialog box appears which warns the user of an ETL600
system reset. By pressing 'Yes', the selected equalizer settings will be downloaded, stored in the
EPROM and after the restart the new equalizer will be activated.
6 Changing the length or mode of a running equalizer
The length ('None', 'Short', 'Middle', 'Long') and/or the mode ('Amplitude response equali-
zation only', 'Combined group delay and amplitude response equalization') of a running
equalizer can be changed without performing a new frequency response measurement. In this
case the new equalizer is based on the measurement of the actual equalizer.
Please note that after downloading the new settings, the equipment is reset in order to activate the
new equalizer. This leads to a short interruption of services on the whole ETL600 link, not only of
the affected channel.
In order to display the frequency response of an equalizer select in 'Equipment' / 'Commissio-
ning and maintenance' / 'Select equalizer' / 'APLC channel X' the equalizer settings of the
equalizer you would like to view and click on the 'View' button. By pressing 'Cancel' the window
can be closed without further action.
Changing the equalizer length or equalizer mode: Select the length and mode of the desired
equalizer and press the 'Download' button. A dialog box appears which warns the user of an
ETL600 system reset. By pressing 'Yes', the selected equalizer settings will be downloaded, stored
in the EPROM and after the restart the new equalizer will be activated.
7 Remote equalizer manipulation
Equalizing a channel or changing the equalizer settings can also be done on the remote ETL600
equipment or anywhere else in the ETL600 network. Using the EOC (in most cases) for remote
access can take several 10 minutes for a complete equalizer operation. Be patient.
It is recommended only to equalize the remote equipment, not any ETL600 further away in an
ETL600 EOC network. In this case a complete channel equalization will take around 20 minutes.
Connect to the desired ETL600 station with the corresponding equipment ID or with the remote
button. Don't forget to set the write access with the correct password. Then follow the procedure
described in chapter 5 and 6 depending on the desired equalizer action. The procedure is the same
except of the longer waiting periods until the necessary data is transmitted over the 100 bps EOC.
8 Application specific equalizer choices
8.1 Rules if external teleprotection in the selected channel is used
If external teleprotection is used on a channel, following additional points must be considered and
understood before equalizing this channel:
Caution
Select the shortest possible equalizer (smallest additional added delay) with flat amplitude
response in the external teleprotection channel. If possible use 'Amplitude response equalization
only'.
Language:
EN
During frequency response measurement, the transmission path of external
teleprotection equipment will be automatically interrupted without further
warnings. For the duration of the measurement, no teleprotection commands
can be transmitted.
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