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FOUNDATION Fieldbus H1 Protocol Device Configuration and Commissioning

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

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PID Control Terminology

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

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Instruction List (IL) Programming

(Will be addressed in future versions of this book)

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Relay Circuits and Ladder Diagrams

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

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Interposing Relays in PLCs

In addition to directly performing logic functions, electromechanical relays may also be used as interposing…

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On/off Electric Motor Control Circuits

An electric motor is often used as a discrete control element in a control system if driving a pump, conveyor…

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Indicators, Recorders, Process Switches and Alarms

So far we have just looked at instruments that sense, control, and influence process variables. Transmitters,…

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Examples of PLC Systems

Programmable logic controllers are essentially nothing more than special-purpose, industrial computers. As…

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Teaching Technical Practices (Labwork)

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

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Ladder Diagram (LD) Structure Commands

The simple PLC ladder diagram (LD) commands consist of contacts and coils, arranged in sequences that mimic…

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Analog Signal Conditioning and Referencing

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

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Safety Instrumented Functions and Systems

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

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Digital PID Controllers

The vast majority of PID controllers in service today are digital in nature. Microprocessors executing PID…

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Policy-based Fortifications

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

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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…

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Feedforward Control

“Feedforward” is a rather under-used control strategy capable of managing a great many types of…

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FOUNDATION Fieldbus Function Blocks

Data-processing modules within FF systems are known as function blocks. Sometimes these blocks serve merely to…

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Limit, Selector, and Override Controls

Another category of control strategies involves the use of signal relays or function blocks with the ability…

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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…

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Interposing Relays in PLCs

In addition to directly performing logic functions, electromechanical relays may also be used as interposing…

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Comparison of Op-Amp Circuits With Analogous Pneumatic Mechanisms

Self-balancing pneumatic instrument mechanisms are very similar to negative-feedback operational amplifier…

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Kirchhoff’s Current and Voltage Laws

Two extremely important principles in electric circuits were codified by Gustav Robert Kirchhoff in the year…

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Dispersive Spectroscopy

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

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Proper Care and Feeding of Pneumatic Instruments

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

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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…

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Single-line Electrical Diagrams

Electrical power grids primarily consist of three-phase AC circuits. This means most power lines (transmission…

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Physics and Chemistry Terminology and Definitions

Atom: the smallest unit of matter that may be isolated by chemical means. Particle: a part of an atom,…

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Circuit Breakers and Disconnects

Disconnect Switches Disconnects are switches designed to isolate sections of a power system in case of damage…

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Practical Measures of Reliability

In reliability engineering, it is important to be able to quantity the reliability (or conversely, the…

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VSD and VFD Motor Drive Features

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

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How to Teach Yourself PLC Programming

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

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Atomic Theory and Chemical Symbols

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

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Instruction List (IL) Programming

(Will be addressed in future versions of this book)

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Laminar Flowmeters

A unique form of differential pressure-based flow measurement deserves its own section in this flow…

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Metric Prefixes and Prefix Scale

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Non-contact Temperature Sensors

Virtually any mass above absolute zero temperature emits electromagnetic radiation (photons, or light) as a…

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Functional Diagrams: the Flow of Information within a Control System

A unique form of technical diagram for describing the abstract functions comprising a control system (e.g. PID…

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Process Flow Diagrams

To show a practical process example, let’s examine three diagrams for a compressor control system,…

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Valve Failure Modes

An important design parameter of a control valve is the position it will “fail” to if it loses…

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