HYSTERESIS

The input to this function block ( The library UTIL.Library\ \) consists of three INT values IN, HIGH and LOW. The output OUT is of type BOOL.

HYSTERESIS in FBD

If IN falls below limit LOW, OUT will get TRUE. Not before in the further run IN exceeds the upper limit, FALSE will be output again, until IN once more falls below LOW and thus OUT again gets TRUE.

Graphical comparison of HYSTERESIS.IN and HYSTERESIS.OUT as a function of time