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