15.1.3 Operation principle IP12360-1 v415.1.3.1 General concepts M11346-77 v1Time definitions M11346-80 v3The error of a clock is the difference between the actual time of the clock, and thetime the clock is intended to have. Clock accuracy indicates the increase in error,that is, the time gained or lost by the clock. A disciplined clock knows its ownfaults and tries to compensate for them.Design of the time system (clock synchronization) GUID-E2B9E81C-5733-4521-B27F-BF33E05CCFB0 v10The time system is based on software and hardware clocks that run independentlyfrom each other (see Figure 276).SW timeTimeregulator(fast or slow)Time tagging and general synchronizationTimeregulator(Setting:seeTechnicalmanual)Commu-nicationEventsSynchronization for differential protection(Echo mode)Diff.commu-nication*IEC 61850-9-2IEC16000002-2-en.vsdxExternalsynchronizationsourcesMergingunits*LONSPASNTPIRIG-BPPSOffMin. pulseDNPIRIG-BPPSOffProtectionand controlfunctionsA/DconverterHW timeOffOnPTP(IEEE 1588)Slave onlyIEC16000002 V2 EN-USFigure 276: Design of the time system (clock synchronization)All time tagging is performed by the software clock. When, for example, a statussignal is changed in the protection system of a function based on the free runninghardware clock, the event is time tagged by the software clock when it reaches theevent recorder. The hardware clock can thus run independently.1MRK 511 424-UEN B Section 15Basic IED functionsBay control REC650 2.2 IEC 617Technical manual
