Online access to the memory objects during operation

For access from the PLC, function blocks from the Beckhoff TcEtherCAT.lib such as FB_EcCoESdoWriteEx can be used. A write call in the form

fbWriteCoE(
sNetId:=sAmsNetId,
nSlaveAddr:= tAmsAddr.port ,
nSubIndex:= 0,
nIndex:= 16#2000 + ((byObjectNo - 1) * 8),
pSrcBuf:= pDataForWrite,
cbBufLen:= wSizeOfData,
bExecute:= TRUE,
tTimeout:= tAdsTimeOut,
bCompleteAccess:= FALSE,
bBusy=> ,
bError=> ,
nErrId=> );

is used in the attached sample program (download).