Latest Energy & Infrastructure Technical Articles

There are many distributed fieldbus capabilities for valve manifolds that can save on network overhead and wiring. In…

There are many distributed fieldbus capabilities for valve manifolds that can save on network overhead and wiring. In this article, we will look at PLC programming of fieldbus manifolds highlighting Festo's CPX layout.

We will show you how to use common math functions from two popular PLC programs—Rockwell Automation's Studio 5000 and…

We will show you how to use common math functions from two popular PLC programs—Rockwell Automation's Studio 5000 and Automation Direct Productivity Suite. 

Counting up and down are commonly required functions in PLC lagger logic programs for tracking inventories, placement…

Counting up and down are commonly required functions in PLC lagger logic programs for tracking inventories, placement patterns, and gaining informational insights about machine performance statistics.

Many PLC commands are well-known to programmers, including contacts, coils, timers, and counters. But a less-common…

Many PLC commands are well-known to programmers, including contacts, coils, timers, and counters. But a less-common instruction is the one-shot, capable of harnessing the incredible processing speeds in a CPU.

One of the most considerable risks in aging control environments is that eventually, spare parts become obsolete and…

One of the most considerable risks in aging control environments is that eventually, spare parts become obsolete and unavailable, and the lack of an upgrade plan can turn a simple failure into a catastrophe.

Credited with coining the name ‘PLC’, Allen-Bradley and parent company Rockwell Automation are major players in the…

Credited with coining the name ‘PLC’, Allen-Bradley and parent company Rockwell Automation are major players in the world of control systems. Learn how the hardware platforms have evolved into the familiar modern configurations.

The timer is a fundamental function of ladder logic programming. In this article, we discuss on- and off-delay as well as…

The timer is a fundamental function of ladder logic programming. In this article, we discuss on- and off-delay as well as retentive timers and define the inputs and outputs required to properly use them.

Power supplies tend to get a reputation as one of the most important power considerations of a DC control circuit - but…

Power supplies tend to get a reputation as one of the most important power considerations of a DC control circuit - but we can’t ignore other key players: power filters, converters, and backup power modules.

What if you could control the end position and the speed of a hydraulic actuator accurately with just a simple signal?…

What if you could control the end position and the speed of a hydraulic actuator accurately with just a simple signal? Some systems use simple open/close valves, but others require far more precision.

Although the are similarities in operating theory, relays and contactors are used in industrial circuits for different…

Although the are similarities in operating theory, relays and contactors are used in industrial circuits for different specific applications, and should not be used interchangeably.

In honor of May the 4th, Star Wars Day, we compare the sources and applications of the two most common force-delivery…

In honor of May the 4th, Star Wars Day, we compare the sources and applications of the two most common force-delivery systems - mechanical and hydraulic.

Two common methods exist for driving induction motors with VFDs - linear scalar control, which is often labeled as V/f,…

Two common methods exist for driving induction motors with VFDs - linear scalar control, which is often labeled as V/f, and vector, or field-oriented control, which can be a bit more complex to understand.

Large DC and AC motor drives often provide terminals for installing a braking resistor. What are these resistors, and how…

Large DC and AC motor drives often provide terminals for installing a braking resistor. What are these resistors, and how do they slow down a machine? What hazards and cautions must be considered?

Redundancy and safety are often seen together in industrial safety systems. Safety relays monitor emergency devices to…

Redundancy and safety are often seen together in industrial safety systems. Safety relays monitor emergency devices to switch contacts based on status - but what makes them different from normal relays?

With the increasing appearance of “web-based” HMIs, we investigate these devices, learn how they differ from the…

With the increasing appearance of “web-based” HMIs, we investigate these devices, learn how they differ from the graphical HMIs, and see implications for our modern control system architecture.

AC motors are common throughout industry - easily controlled by VFDs and without the maintenance that comes with DC…

AC motors are common throughout industry - easily controlled by VFDs and without the maintenance that comes with DC brushes. So then, why are DC motors still used in certain applications?

Before digital control systems, responses were fairly slow. Push a button, and a motor contactor engaged. These days, the…

Before digital control systems, responses were fairly slow. Push a button, and a motor contactor engaged. These days, the speed of computers introduces some new challenges but brings solutions as well.

Modbus is a communication protocol stemming from the early days of Modicon PLCs, but is still common today. These two…

Modbus is a communication protocol stemming from the early days of Modicon PLCs, but is still common today. These two example implementations of Modbus transactions will get you started.

Inductive loads, such as solenoids and contactors, can cause arcs and failures back into electromechanical switching…

Inductive loads, such as solenoids and contactors, can cause arcs and failures back into electromechanical switching devices, causing costly downtime. The solution is cheaper than you think.