Schweitzer Engineering Laboratories SEL-421-4, Instruction Manual

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17.19
Date Code 20171006 Instruction Manual SEL-400 Series Relays
IEC 61850 Communication
Sampled Values
Subscription Reference Stream
SEL SV relays store the smpSynch of each subscribed SV stream in analog quan-
tities SV
mm SNC, where mm is the subscription number. If a CID file is used, the
first subscription stream in the CID file is used as the smpSynch reference. If the
Port 5 SV setting is used, the subscription with the subscribed MAC address set
by SVRADR1 is the first subscription and is used as the smpSynch reference. In
coupled clock mode, any subsequent streams that do not have the same
smpSynch as the time reference are discarded. If the relay stops receiving data
for the first subscription stream, the last smpSynch value received from the first
subscription stream continues to remain as the time reference. If the smpSynch
value of the first subscription stream is zero, only the first subscription stream is
accepted. If the relay operates in freewheeling mode, only the first subscription
stream is accepted.
Station Bus and Process Bus
NOTE:
The MERGED BUSMODE is
not recommended for long-term
operations, as the large amount of
process bus traffic can adversely
affect station bus functions when the
buses are combined.
The SEL SV publishers and subscribers allow flexible station bus and process
bus configurations. If BUSMODE := INDEPEND, station bus traffic (typically
MMS and GOOSE) will only be transmitted out on the station bus ports, and pro-
cess bus traffic (typically SV and GOOSE) will only be transmitted on process
bus ports. If BUSMODE := MERGED, all communications use Port 5A and Port
5B, with process bus and station bus traffic merged on the same physical net-
work, and the process bus ports are disabled. The designation of station bus and
process bus is controlled by NETPORT settings. The station bus port is the same
as the primary port, as specified by NETPORT settings. If NETPORT := A or
NETPORT := B, then Port 5A and Port 5B are used for station bus communica-
tion and Port 5C and Port 5D are used for process bus communication. If
NETPORT := C or NETPORT := D, then Port 5C and Port 5D are used for sta-
tion bus communication and Port 5A and Port 5B are used for process bus com-
munication. IEEE 1588-based time synchronization is only available on Port 5A
and Port 5B. If you want PTP time synchronization on the process bus, use
Port 5A and Port 5B for process-bus communications.
Figure 17.4 shows some
common network configurations, including the NETPORT and BUSMODE set-
tings used.
Figure 17.4 shows an independent bus mode network schematic with PTP time
synchronization on the process bus. In this schematic, the merging unit has set-
tings BUSMODE := INDEPEND and NETPORT := C.
Figure 17.5 shows an independent bus mode network schematic with PTP time
synchronization on the station bus. In this schematic, the merging unit has set-
tings BUSMODE := INDEPEND and NETPORT := A.
Figure 17.4 Independent Bus Mode With PTP Time Synchronization on the
Process Bus
Process Bus
Station Bus
SV Relay SV Relay
Merging Unit
Ethernet Switch
Ethernet Switch
SCADA
Merging Unit
A B C D A B C D
A B C D A B C D
PTP Time
Source