.IndustrialControlSystems.Logical.Counter.Counter

Information

Description

Model 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 <= Max

Where Max is the module of the counter.

Revisions

First release of the Industrial Control Systems: April-May 2012