The transmission data length is set to the arbitrary data length, and thereafter an error detecting {HEAD ~ code} for {TAIL ~ all the data} is added therewith 
for
The transmission data length is set to the arbitrary data length , and thereafter an error detecting { HEAD ~ code } for { TAIL ~ all the data } is added therewith
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH