ABB ETL600 Instruction Manual page 328

Revision:
A
Note:
5 Equalizing a channel
In this section the letter 'X' names the channel to equalize. This can be channel 1, 2 or channel 3.
Do not mix up the channel during the whole equalization process. The selected channel from the
remote to the connected ETL600 system will be equalized.
Please note that equalizing a channel over the EOC network or on the remote side may take
several 10 minutes.
Make a connect with write access to the desired ETL600 equipment and upload the configuration.
Select in the menu bar 'Equipment' / 'Commissioning and maintenance' / 'Frequency
response' / 'APLC channel X'. A dialog box appears telling the user that he is going to disable the
system. By pressing the 'Cancel' button, no channel measurement will be started. By selecting the
'Yes' button, a channel measurement on channel X from the remote to the local ETL600 terminal
will be started. This is also the last chance to abort an equalizer selection process without
interrupting normal services.
Note:
During measurement of the frequency response of the selected channel, voice, data and external
protection are automatically switched off for about one minute. Corresponding alarms may appear.
Protection signal transmission is only possible with NSD600.
After up to 5 minutes, the measurement is finished and the dialog box 'Select equalizer' appears.
The amplitude response of the link from remote equipment to the connected ETL600 can be
viewed for channel X.
With the help of the 'Select equalizer' dialog box, it is possible to select the best possible equalizer
for a specific purpose. When this dialog box first appears, the active equalizer is easily recognised
in the 'Actual equalizer' field. The equalizer delay describes the additional delay added by the
equalizer. The less this delay is, the better it is for applications with external teleprotection
equipment. Please note that the internal teleprotection NSD600 is working independently from this
equalizer delay. The average ripple describes the average ripple left in the complete AF band by
the equalizer. By selecting the desired equalizer before pressing the 'View' button, the frequency
response is visible with and without the equalizer.
In order to return to the 'Select Equalizer' dialog box, select 'Equipment' / 'Commissioning and
maintenance' / 'Select equalizer' / 'APLC channel X' again. It is possible to repeat this procedure
again and again.
If the amplitude response with the equalizer is quite 'noisy', the measurement went wrong due to
sporadic noise on the high voltage line during the measurement. In this case repeat the
measurement by selecting 'Equipment' / 'Commissioning and maintenance' / 'Frequency
response' / 'APLC channel X'.
Note:
Language:
EN
•
External protection equipment, voice, teleoperation and modems will be
automatically disconnected during the channel measurement.
•
Due to sporadic noise and other disturbance during measurement, the
measured channel response can be quite noisy. In this case it is advised
to repeat the channel measurement. During measurement of the
channel, each appearing sporadic noise could jam the measurement.
•
Depending on the configured alarm pick-up and setup time some alarms
could appear for a short moment during channel measurement.
•
During channel measurement, NSD600 teleprotection commands can
still be transmitted without further delay. The measurement will be
cancelled as soon as NSD600 commands are transmitted. If this
happens, the measurement must be repeated.
•
A system reset is performed automatically after downloading new
equalizer settings. As a consequence the link transmission will be
interrupted completely for a moment.
If a system reset or configuration download is performed after a frequency
response measurement before downloading new equalizer settings, all
measurement data are lost.
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