.IndustrialControlSystems.Logical.Counter.Counter .IndustrialControlSystems.Logical.Counter.CounterModel of an Up-Down counter.
At each time step Ts the inputs are
read and the new output values Q and
CV are computed.
In the former image, are reported the S
(Set), R (Reset), CU (CountUP), CD
(CountDown) signals.
The latter images contains the CV
(Current Value) and the PV(Preset
Value).
The counter update the CV when the Set
signal rises, then for each rising edge of the Count Up
(CU) or Count Down (CD) signals the CV is
incremented or decremented by 1.
The Set signal has to be high during this phase, otherwise the
rising edges are not detected.
When the Reset (R) signal rises, the
counter is reset to zero.
Constraints
The current value CV must be
0 <= CV <= MaxWhere Max is the module of the counter.