Variable forcing now uses limited list and buffer instead of systematical instance tree traversal and in-tree "fvalue" to keep track of forced value for pointed variables (external, located). Pointer swapping is performed when forcing externals and located, with backup being restored when forcing is reset. Match Beremiz commit 93ad018fb602.
FUNCTION_BLOCK HYSTERESIS
(* Boolean hysteresis on difference *)
(* of REAL inputs, XIN1 - XIN2 *)
VAR_INPUT XIN1, XIN2, EPS : REAL; END_VAR
VAR_OUTPUT Q : BOOL := 0; END_VAR
IF Q THEN IF XIN1 < (XIN2 - EPS) THEN Q := 0; END_IF ;
ELSIF XIN1 > (XIN2 + EPS) THEN Q := 1 ;
END_IF ;
END_FUNCTION_BLOCK