In programming, a variable that keeps track of the number of iterations of a process. Its value is incremented or decremented with each iteration, and it is compared to a constant or other variable to ...

The way we control the speed of fan motors or pump motors has tremendously changed in the past two decades with the introduction of variable-frequency drives (VFDs), aka variable-frequency controllers ...

In this article, as in industry, advanced process control (APC) refers primarily to multi-variable control. Multivariable control means adjusting multiple single-loop controllers in unison, to meet ...