ABB Relion REC670, Applications Manual

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SMA connector Subminiature version A, A threaded connector with constant
impedance.
SMT Signal matrix tool within PCM600
SMS Station monitoring system
SNTP Simple network time protocol – is used to synchronize
computer clocks on local area networks. This reduces the
requirement to have accurate hardware clocks in every
embedded system in a network. Each embedded node can
instead synchronize with a remote clock, providing the
required accuracy.
SOF Status of fault
SPA Strömberg Protection Acquisition (SPA), a serial master/slave
protocol for point-to-point and ring communication.
SRY Switch for CB ready condition
ST Switch or push button to trip
Starpoint Neutral/Wye point of transformer or generator
SVC Static VAr compensation
TC Trip coil
TCS Trip circuit supervision
TCP Transmission control protocol. The most common transport
layer protocol used on Ethernet and the Internet.
TCP/IP Transmission control protocol over Internet Protocol. The de
facto standard Ethernet protocols incorporated into 4.2BSD
Unix. TCP/IP was developed by DARPA for Internet working
and encompasses both network layer and transport layer
protocols. While TCP and IP specify two protocols at specific
protocol layers, TCP/IP is often used to refer to the entire US
Department of Defense protocol suite based upon these,
including Telnet, FTP, UDP and RDP.
TEF Time delayed gound-fault protection function
TLS Transport Layer Security
TM Transmit (disturbance data)
TNC connector Threaded Neill-Concelman, a threaded constant impedance
version of a BNC connector
TP Trip (recorded fault)
TPZ, TPY, TPX, TPS Current transformer class according to IEC
Section 25
1MRK 511 401-UUS A
Glossary
648 Bay control REC670 2.2 ANSI
Application manual