| Abstract: | Methods are presented for adjusting trigger threshold values to
compensate for drift in the quiescent level of a signal monitored for
initiating a data recording event, thereby avoiding false triggering
conditions. Initial threshold values are periodically adjusted by
re-measuring the quiescent signal level, and adjusting the threshold
values by an offset computation based upon the measured quiescent signal
level drift. Re-computation of the trigger threshold values can be
implemented on time based or counter based criteria. Additionally, a
qualification width counter can be utilized to implement a requirement
that a trigger threshold criterion be met a given number of times prior
to initiating a data recording event, further reducing the possibility of
a false triggering situation. |