Because the Profinet system is a real time system, {HEAD ~ the times} for {TAIL ~ LatchIN} and LatchOUT of the process data are synchronized, so that data is exchanged on all Profinet devices simultaneously 
Because the Profinet system is a real time system , { HEAD ~ the times } for { TAIL ~ LatchIN } and LatchOUT of the process data are synchronized , so that data is exchanged on all Profinet devices simultaneously
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH