Well, I actually said:
... if the software actually looked for an approach to 27' and then busting that height having 'approached' it in a meaningful way, rather than looked for any (instantaneous) height reading below 27' - it might make a bit more sense...
A lot more logic involved than: IF (x = 27') = TRUE Then RETARD
This implies the rate of change should be -ve over a reasonable sample size approaching the condition (x < 27) and that sample should be within certain aboslute values ( e.g. 202'; 147'; 98'; 39' ; -2' (<27' >RETARD)
So 2,000'; 1850'; 5' would NOT produce a LOGICAL TRUE
Requires a simple
first in, first out buffer like a keyboard buffer