Understanding automation selection criteria

Understanding how the programmable logic controller (PLC) has evolved and how it relates to more modern incarnations like the PAC as well as understanding servo system criteria will help a great deal on the plant floor.

06/09/2015


When Dick Morley introduced the programmable logic controller (PLC) in 1968, I wonder if he envisioned how much it would evolve in 47 years. This evolution brought about changes in PLC form factor, functionality, and how PLCs are programmed. In 2001, market research firm ARC introduced the term "programmable automation controller (PAC)" to describe the marked shift in technology behind the ever-evolving PLC.

In this issue's cover story, the author explains the similarities and differences between PLCs and PACs, noting that "PLC-based PAC" is perhaps a better term to describe their convergence-the lines between them is blurring. "Today, it's difficult to find an industrial controller that doesn't display many of the characteristics that might be found in either a PLC or a PAC." There are similarities and differences between them. And, according to the author, the PLC-based PAC is intended to leverage the similarities and minimize the differences. He points out that users should select a controller based on the requirements of the application and not on what it's called.

The other story in this issue examines servo system selection criteria. The authors emphasize that servomotors—and the systems that control them—are not created equal. Servomotors with the same power range from different manufacturers are not necessarily equivalent. Technical aspects, such as torque, inertia, resolution, frequency response, and bandwidth determine servo system performance. In addition to providing a brief servo tutorial, the authors explain why these technical factors must be considered when selecting a servo system. As the authors state in the article, "Servo system selection criteria involves more than just wattage and price."

This article appears in the Applied Automation supplement for Control Engineering and Plant Engineering

- See other articles from the supplement below.



No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Big Data and IIoT value; Monitoring Big Data; Robotics safety standards and programming; Learning about PID
Motor specification guidelines; Understanding multivariable control; Improving a safety instrumented system; 2017 Engineers' Choice Award Winners
Selecting the best controller from several viewpoints; System integrator advice for the IIoT; TSN and real-time Ethernet; Questions to ask when selecting a VFD; Action items for an aging PLC/DCS
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Motion control advances and solutions can help with machine control, automated control on assembly lines, integration of robotics and automation, and machine safety.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Future of oil and gas projects; Reservoir models; The importance of SCADA to oil and gas
Big Data and bigger solutions; Tablet technologies; SCADA developments
SCADA at the junction, Managing risk through maintenance, Moving at the speed of data
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
click me