{HEAD ~ a control unit} that is designed to convert an Ethernet telegram received via the first interface into an internal data telegram and to output {TAIL ~ the internal data telegram} via the second interface 
{ HEAD ~ a control unit } that is designed to convert an Ethernet telegram received via the first interface into an internal data telegram and to output { TAIL ~ the internal data telegram } via the second interface
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH