This block is used to compute the stage index of the plant or of multiple lead/lag units such as pump groups.
At initial time, stage #0 is active. The transition
to stage #1 is triggered when stage #0
has been active for the minimum runtime and when either the Enable
signal u1 has a rising edge or when the stage up
signal u1Up is true.
From stage #i, the transition to stage
#i+1 (resp. i-1) is triggered when stage
#i has been active for the minimum runtime and when
the stage up signal u1Up (resp. stage down signal
u1Dow) is true. From stage
#i, the transition to stage #0 is
triggered when stage #i has been active for the
minimum runtime and the Enable signal u1 is
false.