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1  Introduction 
-Distance protection (ZS/ZG)
-Pilot schemes (DISCAR, DEFCAR)
-Over current protection (OC)
-Earth fault protection (EF)
Control and monitoring application 
-Switch on to fault relay (SOTF)
-Single positon device (SPOS)
-Double positon with sync. (DPSY)
-Software switch controller (SOFTSW)
-Operation time reset (OPTIM)
-Voltage check relay (VCHK)
-Total time measurement (TOTALTIM)
Function identifies and signals (FB) 
-Synchronizing check (SYNDIF)
-Software interlock (ILK)
-Double position device (DPOS)
-Current differential protection (DIF)
-Three positon device (TPOS)
Monitoring and metering functions 
Symbols used in logical diagrams 
-Automatic sequence (ASEQ)