When the first error check routine is completed, the correction controller 105 performs {TAIL ~ a second error check routine} or {HEAD ~ an error verification routine}  
When the first error check routine is completed , the correction controller 105 performs { TAIL ~ a second error check routine } or { HEAD ~ an error verification routine }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH