Upon {TAIL ~ detection} of a trigger, such as the exceeding of {HEAD ~ an error threshold} or the direction of a user, a diagnostic link system enters a diagnostic information transmission mode 
Upon { TAIL ~ detection } of a trigger , such as the exceeding of { HEAD ~ an error threshold } or the direction of a user , a diagnostic link system enters a diagnostic information transmission mode
OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH