One of the most important accessories for any temperature-sensing…
Perhaps the most confusing aspect of discrete sensors is the…
A 4 to 20 mA current signal represents some signal along a 0 to 100…
Fieldbus devices require far more attention in their initial setup and…
Although it seems each model of PLC has its own idiosyncratic standard…
One of the fundamental laws of electric circuits is Kirchhoff’s…
An electric motor is often used as a discrete control element in a…
The purpose of a control valve actuator is to provide the motive force…
A design-based fortification is one rooted in technical details of…
One of the great benefits of digital technology is the ability to…
Learning PLC programming is a very important skill. If your job…
There are multiple motives for compromising the security of an…
Every programmable logic controller must have some means of receiving…
PID control can be a confusing concept to understand. Here, a brief…
These fortifications focus on human behavior rather than system design…
A wise PLC programmer once told me that the first thing any aspiring…
Light has long been used as a long-range signaling medium. While…
Disturbances in the liquid tend to complicate liquid level…
Programmable logic controllers are essentially nothing more than…
The simple PLC ladder diagram (LD) commands consist of contacts and…
Converting between disparate units of measurement is the bane of many…
Measuring the flow rate of liquid through an open channel is not…
As we have seen, feedforward control is a way to improve the stability…
Fluid pressure exerts force on any surface area it contacts, as…
In the United States, the ANSI and IEEE organizations have…
DC electric current signals may also be used to communicate process…
There are multiple motives for compromising the security of an…
Coy, John J. et. al. (December 2012) Sampled graphic illustrations…
Take for instance the problem of measuring fluid flow through a pipe.…
A different strategy for controlling the flow of fluid is to insert a…
An important performance parameter for transmitter instruments is…
Some self-powered (4-wire) analog electronic transmitters are designed…
Abdelaziz, Ahmed (June 2014) Identified numerous typographical errors…
In this section I will show screenshots from a process loop simulation…
Regardless of valve type, all stem-actuated control valves require…
Another category of control strategies involves the use of signal…
One of the most important accessories for any temperature-sensing…
A Safety Instrumented Function, or SIF, is one or more components…
An interesting parallel to the “unity fraction” unit…
Valves can experience a number of problems, most of them either…
