ABB ETL600 Instruction Manual page 240

ABB Switzerland Ltd
Question: The PLC link doesn't work. What can I do to correct this
problem?
Answer: Check the alarms: If there is a hardware alarm at either side
of the link, the reason of it must be found and the problem corrected.
Upload the equipment status and study the alarm messages given by
the HMI600. One single problem can produce a number of such
messages.
If for both equipments of the link no hardware alarms are reported
(anymore), the problem has to be sought in the link. Upload the
equipment status and study the alarm messages given by the HMI600.
It is helpful if it is possible to restrict the problem to one of the following
3 cases:
1.
2.
3.
Case 1: Check the RF settings ( Configuration / System / Channel
settings ) and the hardware on the RF-side. Check the tuning of the
RF transmit and receive filters and the adjustment of the Rx RF level
potentiometer. Work along the RF path: RF cables, RF terminating
plate, RF coupling filter. Check the frequency response of the line.
Case 2: The level of the line noise is given by the high voltage line
itself and by the atmospheric conditions along the line. The only way to
combat the noise is to increase the RF signal power or to reduce the
RF signal bandwidth.
Case 3: Look out for other equipment parallel PLC terminals
connected to the same line. Check for signal saturation in the RF
signal path.
Question: Some alarms are present, signaled by alarm relay contacts
and/or alarm LEDs.
Answer: Upload status data to see the details about the causes of the
alarms. If both hardware and link alarms are present, first remove the
cause of the hardware alarm. After this has been done, upload system
status once again and – if a link alarm should still be present – find the
cause of the link alarm. Check whether the alarm threshold levels are
appropriate.
Question: How are the outputs on the Teleprotection Interface G4AI
operated, if they are configured as alarm outputs? And what about the
LEDs of the outputs on the front panel?
Answer: The relay contacts on G4AI are operated in the same way
than the alarm relays on the RF-Converter P4LT or on the Alarm Relay
9-14
1KHW001489-EN
Excessive signal attenuation,
Excessive line noise,
Excessive distortion.
November 2005
ETL600
Troubleshooting