A bus coupler for exchanging data between {HEAD ~ a network} constructed for transmitting {TAIL ~ Ethernet telegrams} and a lower level bus system , comprising: 
constructed for transmitting
A bus coupler for exchanging data between { HEAD ~ a network } constructed for transmitting { TAIL ~ Ethernet telegrams } and a lower level bus system , comprising :
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH