ABB ETL600 Instruction Manual page 338

Revision:
A
4. Click Start measurement and wait until the measured Rx RF level appears in the dialog
box.
Note:
5. The HMI600 selectively measures the level of the RF signal from the own transmitter.
This level is set to a minimum with the aid of a balancing network (resistance with jumper
RA/RB/RC/RD/RP and potentiometer R226, inductance with jumper LA – LN/LP and
capacitance with jumpers CA to CL, CP) as described below.
6. Reduce the measured Rx RF level moving the R-jumper between RA, RB, RD, RD and
RP. When the best jumper position has been found, turn potentiometer R226 until a first
minimum is reached.
7. Search for the next minimum by moving the L-jumper sequentially to LA, LB, LC, ..., LN.
If, however, jumper LA does not produce any reduction, set Jumper LP. (LA produces the
smallest inductive current and LN the largest).
Note:
8. If a minimum could be achieved with LA to LN, reduce the measured Rx RF level
again to the next minimum using potentiometer R226. Further improvement can be
achieved using small capacitor values with jumpers CA, CB or CC. C jumpers may be
inserted in parallel.
This concludes the tuning of the hybrid.
Click Stop measurement and Cancel to close the dialog box.
9. If no minimum could be achieved with LA to LN, reduce the level using jumpers CA –
CN until the next minimum is reached. The capacitors are binary weighted with CA the
smallest and CN the largest capacitor. C jumpers may be inserted in parallel.
Conclude the tuning by adjusting R226 for the next minimum.
Click Stop measurement and Cancel to close the dialog box.
C.6.5 SNR pilot
1. In menu Equipment click Upload status.
2. Check signal to noise ratio (SNR) of the pilots of the configured APLC channels.
C.7 Equalization
Refer to 1KHW001494 'APLC Channel Equalization for ETL600'. The document is put into a short
instruction, printed in the following chapters C.7.1 and C.7.2.
Note:
Note:
C.7.1 Measure frequency response
It is assumed, that
- the RF tuning of the remote equipment is already finished. If it isn't finished, tune the remote
equipment.
- the link works and all alarms are cleared.
Measure the frequency response as described in 1KHW001494 'APLC Channel equalization for
ETL600':
Language:
EN
It is possible that the operator phone of remote equipment is ringing during
the measurement. This has no effect on the measurement.
Only one L jumper (LA – LN) may be inserted at any time
The equalization routine can also be done at the remote equipment via EOC
communication.
If telephony is configured with a speech cut off frequency of 3400 Hz in any of
the APLC channels, the equalizer must be enabled for each of these channels.
When configuring the equalizer (dialog box Equipment / Commissioning and
maintenance / Select equalizer), press the radio buttons Long and
Amplitude equalization only.
Page:
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