Latest PLCs & PACs Education

Categories

Memory Maps and I/O Addressing

Memory Maps and I/O Addressing

A wise PLC programmer once told me that the first thing any aspiring programmer should learn about the PLC…


Textbook

Concepts and Laws of Probability

Concepts and Laws of Probability

While the term “probability” may evoke images of imprecision, probability is in fact an exact…


Textbook

Safety Instrumented Functions and Systems

Safety Instrumented Functions and Systems

A Safety Instrumented Function, or SIF, is one or more components designed to execute a specific…


Textbook

Relating 4 to 20 mA Signals to Instrument Variables

Relating 4 to 20 mA Signals to Instrument Variables

A 4 to 20 mA current signal represents some signal along a 0 to 100 percent scale. Usually, this scale is…


Textbook

Relay Circuits and Ladder Diagrams

Relay Circuits and Ladder Diagrams

Electromechanical relays may be connected together to perform logic and control functions, acting as logic…


Textbook

VSD and VFD Motor Drive Features

VSD and VFD Motor Drive Features

Modern DC and AC motor drives provide features useful when using electric motors as final control elements.…


Textbook

Analog Signal Conditioning and Referencing

Analog Signal Conditioning and Referencing

Modern analog-to-digital converters are phenomenally accurate, dependable, repeatable, and surprisingly…


Textbook

Level Sensor Accessories

Level Sensor Accessories

Disturbances in the liquid tend to complicate liquid level measurement. These disturbances may result from…


Textbook

Introduction to Power System Automation

Introduction to Power System Automation

Those familiar with industrial instrumentation will find much within the electric power industry remarkably…


Textbook

Legal Code

Legal Code

Creative Commons Attribution 4.0 International Public License By exercising the Licensed Rights (defined…


Textbook

PID Control Terminology

PID Control Terminology

PID control can be a confusing concept to understand. Here, a brief summary of each term within PID (P. I, and…


Textbook

FOUNDATION Fieldbus H1 Protocol Device Configuration and Commissioning

FOUNDATION Fieldbus H1 Protocol Device Configuration and Commissioning

Fieldbus devices require far more attention in their initial setup and commissioning than their analog…


Textbook

Ladder Diagram (LD) Programming Contacts and Coils

Ladder Diagram (LD) Programming Contacts and Coils

In the United States, the most common language used to program PLCs is Ladder Diagram (LD), also known as…


Textbook

How to Teach Yourself PLC Programming

How to Teach Yourself PLC Programming

Learning PLC programming is a very important skill. If your job involves programming, then you will likely…


Textbook

WirelessHART Radio Communication Standard

WirelessHART Radio Communication Standard

An exciting development in industrial instrumentation is the WirelessHART radio communication standard,…


Textbook

Introduction to Modbus

Introduction to Modbus

Developed by the Modicon company (the original manufacturer of the Programmable Logic Controller, or PLC) in…


Textbook

Electrical Signal and Control Wiring

Electrical Signal and Control Wiring

There is much to be said for neatness of assembly in electrical signal wiring. Even though the electrons…


Textbook

Teaching Technical Practices (Labwork)

Teaching Technical Practices (Labwork)

Labwork is an essential part of any science-based curriculum. Here, much improvement may be made over the…


Textbook

Common Diagnostic Mistakes in Control Systems

Common Diagnostic Mistakes in Control Systems

Volumes could be written about poor diagnostic technique. The following mistakes are not intended to comprise…


Textbook

Human-Machine Interfaces (HMIs)

Human-Machine Interfaces (HMIs)

Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…


Textbook

Instrument Turndown (Rangedown)

Instrument Turndown (Rangedown)

An important performance parameter for transmitter instruments is something often referred to as turndown or…


Textbook

Introduction to Calculus

Introduction to Calculus

Calculus. Few areas of mathematics are as powerfully useful in describing and analyzing the physical…


Textbook

Derivative (Rate) Control

Derivative (Rate) Control

The final element of PID control is the “D” term, which stands for derivative. This is a calculus…


Textbook

Metering Pumps

Metering Pumps

A very common method for directly controlling low flow rates of fluids is to use a device known as a metering…


Textbook

What is Electrical Power?

What is Electrical Power?

Since we often use electricity to convey energy from one location to another, it is important to be able to…


Textbook

Electronic Structure

Electronic Structure

Earlier in this chapter you were shown a model of a nitrogen atom with a dense nucleus (comprised of protons…


Textbook

Motives for Compromising the Security of an Industrial Control System

Motives for Compromising the Security of an Industrial Control System

There are multiple motives for compromising the security of an industrial control system, some of which…


Textbook

Glossary of Cyber-security Terms

Glossary of Cyber-security Terms

Cyber-security seems to have its own vocabulary, ranging from unwieldy technical acronyms to slang terms…


Textbook

Calibration Procedures in Linear, Non-Linear and Discrete Instruments

Calibration Procedures in Linear, Non-Linear and Discrete Instruments

As described earlier in this chapter, calibration refers to the adjustment of an instrument so its output…


Textbook

Self-regulating, Integrating, and Runaway Process Characteristics

Self-regulating, Integrating, and Runaway Process Characteristics

Perhaps the most important rule of controller tuning is to know the process before attempting to adjust the…


Textbook

Rotating Phasor in Three-dimensional Form

Rotating Phasor in Three-dimensional Form

The following animation shows a rotating phasor in three-dimensional form. The phasor rotates in a complex…


Textbook

Flow Switches

Flow Switches

A flow switch is one that detects the flow of some fluid through a pipe. Flow switches often use…


Textbook

Teaching Technical Theory

Teaching Technical Theory

Learning is not merely a process of information transfer. It is first and foremost a transformation of…


Textbook

Problem-solving by Simplification

Problem-solving by Simplification

A whole class of problem-solving techniques focuses on altering the given problem into a simpler form that is…


Textbook

Unit Conversions and Physical Constants

Unit Conversions and Physical Constants

Converting between disparate units of measurement is the bane of many science students. The problem is worse…


Textbook

Wastewater Disinfection Example

Wastewater Disinfection Example

The final step in treating wastewater before releasing it into the natural environment is to kill any harmful…


Textbook

Level Switches

Level Switches

A level switch is one detecting the level of liquid or solid (granules or powder) in a vessel. Level switches…


Textbook

Dispersive Spectroscopy

Dispersive Spectroscopy

The dispersion of visible light into its constituent colors goes all the way back to the 17th century with…


Textbook

P, I, and D Responses Graphed

P, I, and D Responses Graphed

Visualizing the actions of P, I, and D tuning parameters using graphs is extremely useful in predicting the…


Textbook

AC Motor Speed Control

AC Motor Speed Control

AC induction motors are based on the principle of a rotating magnetic field produced by a set of stationary…


Textbook

Null-balance Voltage Measurement

Null-balance Voltage Measurement

A number of different sensors used in instrumentation generate DC voltage signals proportional to the process…


Textbook

Proper Care and Feeding of Pneumatic Instruments

Proper Care and Feeding of Pneumatic Instruments

Perhaps the most important rule to obey when using pneumatic instruments is to maintain clean and dry…


Textbook

Radio-energy Pulse in Guided-wave Radar Level Measurement

Radio-energy Pulse in Guided-wave Radar Level Measurement

The following animation shows how a radio-energy pulse travels down and then up the waveguide of a guided-wave…


Textbook

FOUNDATION Fieldbus H1 Protocol Data Link Layer

FOUNDATION Fieldbus H1 Protocol Data Link Layer

Like so many other industrial data networks, FOUNDATION Fieldbus is an “unswitched” or…


Textbook

Classified Areas and Electrical Safety Measures

Classified Areas and Electrical Safety Measures

Any physical location in an industrial facility harboring the potential of explosion due to the presence of…


Textbook

Human-Machine Interfaces (HMIs)

Human-Machine Interfaces (HMIs)

Human-machine interfaces, or HMIs, are a critical part of nearly all control systems, complementing the…


Textbook

Equivalent Series and Parallel Circuits

Equivalent Series and Parallel Circuits

Impedance in a series circuit is the orthogonal sum of resistance and reactance: \[Z = \sqrt{R^2 + (X_L -…


Textbook

Hand Switches and Stackable Switches

Hand Switches and Stackable Switches

A hand switch is exactly what the name implies: an electrical switch actuated by a person’s hand motion.…


Textbook

Glossary of Cyber-security Terms

Glossary of Cyber-security Terms

Cyber-security seems to have its own vocabulary, ranging from unwieldy technical acronyms to slang terms…


Textbook

Ratio Control

Ratio Control

Most people reading this book have likely had the experience of adjusting water temperature using two hand…


Textbook

Energy in Chemical Reactions

Energy in Chemical Reactions

A chemical reaction resulting in a net release of energy is called exothermic. Conversely, a chemical reaction…


Textbook

Periodic Table of the Ions

Periodic Table of the Ions


Textbook

Process and Instrument Diagrams

Process and Instrument Diagrams

The next level of detail is the Process and Instrument Diagram, or P&ID. Here, we see a “zooming…


Textbook

Formulae for Common Chemical Compounds

Formulae for Common Chemical Compounds

Most of these formulae appear in molecular chemical form rather than structural form. For example, ethanol…


Textbook

Policy-based Fortifications

Policy-based Fortifications

These fortifications focus on human behavior rather than system design or component selection. In some ways…


Textbook

Numerical Differentiation

Numerical Differentiation

As we have seen, the concept of differentiation is finding the rate-of-change of one variable compared to…


Textbook

New Content

New Content

Coy, John J. et. al. (December 2012) Sampled graphic illustrations from his NASA Reference Publication…


Textbook

Integral (Reset) Control

Integral (Reset) Control

Imagine a liquid-level control system for a vessel, where the position of a level-sensing float sets the…


Textbook

Introduction to Inductors and Inductance

Introduction to Inductors and Inductance

Any conductor possesses a characteristic called inductance: the ability to store energy in the form of a…


Textbook

Atomic Theory and Chemical Symbols

Atomic Theory and Chemical Symbols

The three “elementary” particles of matter comprising all atoms are electrons, protons, and…


Textbook