Let us discuss a steam-heated reactor control system with a cascade strategy, where the temperature controller drives a setpoint signal…
The direction of action for a loop controller – either direct or reverse – at first seems like a very…
An “override” control strategy involves a selection between two or more controller output signals, where only one controller at a…
In the broadest sense, a “selector” control strategy is where one signal is selected from multiple signals in a system…
A common application for select and limit functions is in cascade control strategies, where the output of one controller becomes…
Another category of control strategies involves the use of signal relays or function blocks with the ability to switch between…
As we have discussed, feedforward control is a way to improve the stability of a feedback control system in the…
Feedforward control works by directly modulating the manipulated variable in a control system according to changes sensed in the load(s).…
Let us consider a liquid level control system on an open tank, where three different fluid ingredients (shown in the…
“Feedforward” is a rather under-used control strategy capable of managing a great many types of process problems. It is based…
