Industrial Control Systems - Instrumentation Tools

Limit, Selector, and Override controls

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

A control strategy similar to ratio control is relation control. This is similar to ratio control in that a “wild”

Most people reading this article have likely had the experience of adjusting water temperature using two hand valves as they

An example of ratio control at work is in a process whereby hydrocarbon gases (usually methane) are converted into hydrogen

A simple control system drawn in block diagram form looks like this: Information from the measuring device (e.g. transmitter) goes

In a manually-controlled process, a human operator directly actuates some form of final control element (usually a valve) to influence