Feedback: Criteria for PLC vs. DCS evaluation

11/17/2006


I read your article about the Eli Lilly engineer’s (Mike Alward) comparison of PLC versus DCS. [ Control Engineering Weekly News email newsletter, Oct. 31, 2006; “ Automation Fair: Pharma engineer rates PLC system over DCS .”]

What were the 19 criteria used to compare? This is so I can understand the viewpoint of giving a 77-73 lead to the PLC. We do run into the comparison once in awhile, and, yes, it [the DCS advantage] does seem to disappear, as PLC functionality gets closer to the DCS. Thank you.
—James Pfeifer, R.E.T., F.S.E, senior control systems specialist, IMV Projects , Calgary, Alberta, Canada

PLC vs. DCS criteria are…
I appreciate your feedback on the PLC versus DCS debate. For those just picking up the discussion, the article, linked above, compares a control system based on programmable logic controllers and distributed control systems. While I included some criteria provided by Mike Alward, lead system architect at Eli Lilly (Indianapolis, IN), I should have figured readers would want them all.

Here are the 19 criteria Alward mentioned:

  1. Control execution speed

  2. Control templates provided

  3. Control templates, ability to create

  4. Control, advanced

  5. Control, analog

  6. Control, machine

  7. Cost for implemented system

  8. Global tag, parameter accessibility

  9. HMI development / integration

  10. Integrated hardware solution

  11. Integrated software solution

  12. Integration of non-vendor provided components and applications

  13. OEM equipment, ease of integration with

  14. Programming language capabilities

  15. Recipe functionality

  16. Redundancy, fault tolerance

  17. Scalability

  18. Security, logical

  19. System integrators, availability of effective

For more Control Engineering research and trends on PLCs and on process control, read:

Also, type the words control systems in the search box atop any page at www.controleng.com for other related reading.

—Mark T. Hoske , Control Engineering editor in chief





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.
Intelligent, efficient PLC programming: Cost-saving programming languages are available now; Automation system upgrades; Help from the cloud; Improving flow control; System integration tips
Smarter machines require smarter systems; Fixing PID, part 3; Process safety; Hardware and software integration; Legalities: Integrated lean project delivery
Choosing controllers: PLCs, PACs, IPCs, DCS? What's best for your application?; Wireless trends; Design, integration; Manufacturing Day; Product Exclusive
PLCs, robots, and the quest for a single controller; how OEE is key to automation solutions.
This article collection contains several articles on improving the use of PID.
Learn how Industry 4.0 adds supply chain efficiency, optimizes pricing, improves quality, and more.

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

Special report: U.S. natural gas; LNG transport technologies evolve to meet market demand; Understanding new methane regulations; Predictive maintenance for gas pipeline compressors
Cyber security cost-efficient for industrial control systems; Extracting full value from operational data; Managing cyber security risks
Drilling for Big Data: Managing the flow of information; Big data drilldown series: Challenge and opportunity; OT to IT: Creating a circle of improvement; Industry loses best workers, again