manual_ect_clu_e

EtherCAT
Realtime Master Library
Documentation
SYBERA Copyright © 2014
6.6 EtherCAT LowLevel Distributed Clock Functions
The EtherCAT realtime library provides functions for propagation delay compensation,
sytem time offset compensation and drift compensation. Additionaly DC sync control can
be managed. Therefore several functions are exported as low level functions.
The distributed clock functions are to be used directly after change ti PRE-OPERATIONAL
state.
6.6.1 DC Local Time
This function latches out the local time of all stations.
ULONG Result = Ecat(32/64)ReadDcLocalTime(VOID);
6.6.2 DC Propagation Delay Compensation
This function compensates the propagation delay for the stations relations
ULONG Result = Ecat(32/64)CompDcPropDelay(VOID);
6.6.3 DC Offset Compensation
This function compensates the offset of station local time and the reference local time (first
DC slave)
ULONG Result = Ecat(32/64)CompDcOffset(VOID);
6.6.4 DC Drift Compensation
This function compensates the drift of the DC station clock by writing ARMW commands at
least 3 seconds.
ULONG Result = Ecat(32/64)CompDcDrift(ULONG InitTime);
6.6.5 DC Quality Check
This function checks the quality of DC synchronisation. It returns the max. system time
difference in [nsec] among all stations. Additionally the individual system time difference is
written to DC_LOCAL_TIME structure of each station.
ULONG Result = Ecat(32/64)CheckDcQuality(PULONG pMaxSysTimeDiff);
SYBERA GmbH, Hohenzollernstr. 2, 71088 Holzgerlingen, Germany, Tel: +49-7031-411-781 Page 54