SC
Switch or push button to close
SCL
Short circuit location
SCS
Station control system
SCADA
Supervision, control and data acquisition
SCT
System configuration tool according to standard IEC 61850
SDU
Service data unit
SELV circuit
Safety Extra-Low Voltage circuit type according to IEC60255-27
SFP
Small form-factor pluggable (abbreviation)
Optical Ethernet port (explanation)
SLM
Serial communication module.
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 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 earth-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 10
1MRK 500 127-UEN D
Glossary
90
670 series
Operation manual
