Schweitzer Engineering Laboratories SEL-751 - Figure I.4 TCP Connection

I.10
SEL-751 Relay Instruction Manual Date Code 20170927
Synchrophasors
Ethernet Port Settings for IEEE C37.118 Synchrophasors
PMOTS1 and PMOTS2
Selects the PMU Output transport scheme for Session 1 and Session 2,
respectively.
PMOTSn := TCP. establishes a single, persistent TCP socket for transmitting
and receiving synchrophasor messages (both commands and data), as
illustrated in Figure I.4.
Figure I.4 TCP Connection
PMOTSn := UDP_T. establishes two socket connections. A non-persistent
TCP connection is used for receiving synchrophasor command messages as
well as synchrophasor configuration and header response messages. A
persistent UDP connection is used to transmit synchrophasor data messages.
Figure I.5 depicts the UDP_T connection.
PMOTSn := UDP_U. uses the same connection scheme as the UDP_T except
the synchrophasor configuration and header response messages are sent over
the UDP connection, as shown in Figure I.5.
Figure I.5 UDP_T and UDP_U Connections
PMOTSn := UDP_S. establishes a single persistent UDP socket to transmit
synchrophasor messages. Synchrophasor data are transmitted whenever new
data are read. With this communication scheme, the relay sends a
“Synchrophasor Configuration Response 2” once every minute, as shown in
Figure I.6.
C37.118
- Synchrophasor Command Start Request
- Synchrophasor Command Stop Request
- Synchrophasor Command Configuration Request 1
- Synchrophasor Command Configuration Request 2
- Synchrophasor Command Header Frame Request
- Synchrophasor Command Extended Frame
C37.118
- Synchrophasor Measurement
- Synchrophasor Configuration Response 1
- Synchrophasor Configuration Response 2
- Synchrophasor Header Frame
SEL-751
(Persistent)
TCP Socket
C37.118
- Synchrophasor Command Start Request
- Synchrophasor Command Stop Request
- Synchrophasor Command Configuration Request 1
- Synchrophasor Command Configuration Request 2
- Synchrophasor Command Header Frame Request
- Synchrophasor Command Extended Frame
If PMOTSx is UDP_T
- Synchrophasor Configuration Response 1
- Synchrophasor Configuration Response 2
- Synchrophasor Header Frame Response
SEL-751
(Persistent)
TCP Socket
(Persistent)
UDP Socket
C37.118
- Synchrophasor Measurement
If PMOTSx is UDP_U
- Synchrophasor Configuration Response 1
- Synchrophasor Configuration Response 2
- Synchrophasor Header Frame Response
NOTE: The UDP setting (UDP_T,
UDP_U, and UDP_S) allows for both
Multicast and Unicast IP addresses.