Detecting Communication Faults On Transceiver 21-216; Detecting Communication Faults On Transceiver 21-219 - Hitachi 670 Series Application Manual

1MRK505382-UEN Rev. K
LHMI info
Setting/signal
NOCARR
NOMESS
LNGTHERR
YBIT
LOWLEVEL
1) Approximately 75% RXD is typical if, for example, two master clocks are present in the telecommunication network.
5.7.2

Detecting communication faults on transceiver 21-216

Some LED indicators on the transceiver 21–216 front panel can be used for communication fault
tracing as shown in Table 31.
Table 31:
LED name
RA
LA
If the line differential protection IED shows a communication fail alarm but RA or LA LED is not lit on
transceiver 21-216, communication interruption stems from the telecommunication network.
5.7.3

Detecting communication faults on transceiver 21-219

Some LED indicators on the transceiver 21–219 front panel can be used for communication fault
tracing as shown in Table
Communication set-up, 670/650 series
Application Guide
Normal Faulty
(example) (example)
0
0
0
0
0
LED indicators used for detecting communication faults
Fault indication
Remote Alarm. Red LED indicates that the remote unit has detected a fault condition, and has
set the Yellow Alarm bit in the C37.94 protocol.
Local Alarm. Red LED indicates that transceiver 21-206 has detected a fault condition in the
C37.94 protocol (LOS = Loss Of Signal). The Yellow Alarm bit is set in the outgoing C37.94
protocol.
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Specification
1 Status
1 Status
1 Status
1 Status
1 Status
Communication set-up
Description
No carrier is detected in the incoming
message. Group signal - Logical OR for:
• LINK_LOST (no input data stream at
the optical receiver)
• SYNC_LOST (clock synchronization
is lost)
• C37 ERROR (error at the C37.94
fiberoptic receiver: faulty format)
No start and stop flags in the incoming
message
Incorrect length for the incoming message
Detected error in an incoming message at
the remote end
Low signal level in the receive link
GUID-A0B9019C-F470-49AA-AD36-56B1FCCB5E01 v1
GUID-4652FF2A-E9C1-4EEF-A764-8A9B413E9FC3 v1
Section 5
89