Schweitzer Engineering Laboratories SEL-2701 - Table 3.14 GOOSE Sender IED Display Information; Figure

3.13
Date Code 20020501 SEL-2701 Ethernet Processor Instruction Manual
Settings and Commands
SEL-2701 Commands
Also use the GOOSE command to display GOOSE monitoring information.
You can include an optional parameter for the number of times to display the
information. The information displayed for each GOOSE ID is described in
Table 3.14.
Because there may be many IEDs on a UCA2 network sending GOOSE
messages, each device that receives GOOSE messages implements a filtering
mechanism. By filtering messages, the SEL-2701 drastically reduces message
processing by ignoring messages that it does not need. This increases overall
GOOSE performance of the SEL-2701 and host.
The SEL-2701 filters GOOSE messages according to the Ethernet multicast
group in each GOOSE message. The SEL-2701 uses the GOOSE monitor
settings in Table 3.7 on page 3.8 to build a table of Ethernet multicast groups
that it will monitor. Each GOOSE message contains a text GOOSE ID and an
Ethernet multicast address. The SEL-2701 listens for GOOSE messages and
captures the Ethernet multicast group associated with each GOOSE device
that the SEL-2701 is programmed to monitor. The SEL-2701 then processes
only messages from the Ethernet multicast addresses that it has collected.
When you first power up the SEL-2701, use the GOOSE R command, or
change the SEL-2701 UCA2 settings, the SEL-2701 listens for GOOSE
messages for two minutes to build a table of Ethernet multicast addresses.
Because each GOOSE device sends a GOOSE message if there is a state
change or every minute if there are no state changes, a two-minute listening
period is sufficient to detect all active GOOSE devices.
After the SEL-2701 completes the listening process, it only processes
Ethernet multicast messages from devices that it identified during the listening
process. If a device fails to send a GOOSE message during the listening
process, the SEL-2701 will ignore all future messages from the device.
When you use the GOOSE command to display GOOSE statistics, the
Ethernet multicast group is shown for each IED that the SEL-2701 is
monitoring for GOOSE messages. If the SEL-2701 is in listening mode, or if
it has not resolved a GOOSE text ID within the two-minute listening process,
the SEL-2701 displays $$-$$-$$-$$-$$-$$ for the Ethernet multicast group.
The SEL-2701 tracks GOOSE messages, compiles GOOSE statistics, and
decides if the GOOSE ID is inactive. Use the GOOSE command to display
this information. An example response to the GOOSE command is shown in
Figure 3.1 on page 3.14.
Table 3.14 GOOSE Sender IED Display Information
Information Description
Multicast Group GOOSE sender Ethernet multicast group
GOOSE ID Text name for GOOSE sender
StNum Hexadecimal state number that increments with each state change
SqNum Hexadecimal sequence number that increments with each GOOSE
message
HoldTime GOOSE message time to live
Timed Out GOOSE sender inactive indication string
BackTime Time in milliseconds since last status change