ABB ETL600 Instruction Manual page 337

Revision:
A
3. Click the button Calculate thresholds. This sets the alarms thresholds for pilot level,
SNR level and the AGC blocking level of each configured APLC channel to the following
values:
4. Close the dialog box by clicking OK.
5. On the Equipment menu click Download configuration.
6. Click Yes, OK and Yes in the following message boxes (default buttons).
C.6.3 Check link alarms
If the remote equipment is operational, the link alarm of the local equipment should be OFF in a
few seconds.
Verify that the link alarm of the remote equipment is OFF as well. There are several ways to do
that:
- Connect to the remote equipment with HMI600 and upload the status.
- Program one of the R1BC user alarms to the link alarm of the remote equipment and view this
user alarm in the alarm status of the local equipment
- Activate Alarm Polling for the remote equipment.
C.6.4 Tune RF hybrid P3LE
The goal of hybrid tuning is to increase the trans-hybrid loss, which reduces the amount of signal of
the local transmitter entering the local receiver.
Note:
Note:
The RF line coaxial cable is connected to the equipment. The PCB extender type I9BK or the Tx
tuning adapter P3LL is inserted in place of the RF hybrid P3LE and the RF hybrid is plugged on top
of it.
The settings on P3LL if used are:
•
Function:
•
Position of S1:
•
Position of S2:
•
Position of S3:
•
Position of LOAD:
Tuning the hybrid using the HMI600.
1. On the Equipment menu click Tuning & testing. This opens the Tuning & testing dialog
box.
2. Click Tune RF hybrid. This opens the Tune RF hybrid dialog box.
3. Check the jumper setting for the line-balancing network on the hybrid: RA, LP, CD and
CE must be set. The remaining C-jumpers must be in P position.
Check if the impedance is correctly set to 45, 75 or 125 Ohm with jumpers LNx, Mx and
Nx, where x=1 for 45 Ohm, x=2 for 75 Ohm and x= 3 for 125 Ohm, nearest to the
impedance of the coupling filter.
Language:
EN
Pilot level alarm threshold:
SNR alarm threshold:
AGC blocking level:
The tuning is not necessary when the ETL600 is operated without Rx filter
P4RX. In this case, default settings must be used:
- Jumpers RA, LP, CD and CE set and the remaining C-jumpers in P position.
- Hybrid impedance chosen nearest to the impedance of the coupling filter,
i.e. 45, 75 or 125 Ohm with jumpers LNx, Mx and Nx, where x=1 for 45
Ohm, x=2 for 75 Ohm and x= 3 for 125 Ohm.
The transhybrid loss that has been achieved by tuning the hybrid is equal to the
increase of the measured RF level when the RF cable is unplugged. If it is
higher than 20 dB, the tuning can be considered as successful and may be
terminated.
B
L1, FILTER
FILTER
LINE
LINE
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Actual pilot level – 12 dB
12 dB
Actual pilot level – 18 dB
1KHW001495-EN