Sel 411L - Table 11.13 Channel Configuration and Status Section

P.11.42
SEL-411L Relay Protection Manual Date Code 20151029
Testing and Troubleshooting
Relay Self-Tests
Channel Statistics
These measurements provide longer-term indications on the health of the 87L
communications and may be used to identify transient problems.
Table 11.13 Channel Configuration and Status Section
Channel Status Indicates if a channel is healthy or is in alarm. An
alarm will be declared if
➤ The channel receive status is not OK, or
➤ The channel has high packet loss, or
➤ The channel has high latency, or
➤ The channel has high asymmetry, or
➤ The channel is not synchronized.
Each of these events is identified below.
Medium/Protocol Identifies the particular hardware employed by the
channel: Ethernet, G.703, RS422, or direct fiber.
Remote relay ID Indicates the ID of the remote relay. This ID must
match the local ID of the relay at the far end of the
channel. In the case of Ethernet the 87LMAC
address and 87LVLAN settings are reported.
Application Indicates that the channel is:
➤ Available
a
- the channel is OK but not in use or
➤ In-use - The channel is OK and is in use or
➤ Failed - The channel is not OK
a
Applicable to dual redundant channel applications.
In dual redundant applications this entry also
indicates whether the channel is the primary or
standby channel.
Receive Status Indicates that the channel is receiving data (the
channel is OK) or is not receiving data (the channel
has failed).
High Packet Loss Declared if the number of packets that were lost in
the last 40 seconds exceeds the lost packet alarm
threshold setting. This alarm is an indication of
degradation of the communications media or its
associated hardware.
High Latency Declared if the round trip channel delay exceeds the
maximum round-trip delay setting. This alarm is
another indication that the channel may be out-of-
specified operation.
High Asymmetry Declared on channels using time-based
synchronization if the difference between the
channel delay in transmit and receive direction
exceeds the maximum asymmetry setting. This
alarm may be an indication that channel switching
has occurred on a multiplexed communications
network. It should be noted that channel switching
increases the availability of the channel by switching
between redundant paths. However, frequent
switching or asymmetrical switching should be
investigated.
Packets lost—40 second A count of the number of packets lost over the last
40 seconds. Increasing packet loss is an indication of
a failing channel.