PCI Peripheral component interconnect, a local data bus
PCM Pulse code modulation
PCM600 Protection and control IED manager
PC-MIP Mezzanine card standard
PELV circuit Protected Extra-Low Voltage circuit type according to
IEC60255-27
PMC PCI Mezzanine card
POR Permissive overreach
POTT Permissive overreach transfer trip
Process bus Bus or LAN used at the process level, that is, in near
proximity to the measured and/or controlled components
PRP Parallel redundancy protocol
PSM Power supply module
PST Parameter setting tool within PCM600
PTP Precision time protocol
PT ratio Potential transformer or voltage transformer ratio
PUTT Permissive underreach transfer trip
RASC Synchrocheck relay, COMBIFLEX
RCA Relay characteristic angle
RISC Reduced instruction set computer
RMS value Root mean square value
RS422 A balanced serial interface for the transmission of digital data
in point-to-point connections
RS485 Serial link according to EIA standard RS485
RTC Real-time clock
RTU Remote terminal unit
SA Substation Automation
SBO Select-before-operate
SC Switch or push button to close
SCL Short circuit location
SCS Station control system
SCADA Supervision, control and data acquisition
1MRK 511 391-UUS C Section 5
Glossary
670 series 2.2 ANSI 55
Communication protocol manual