Wednesday, September 30, 2015

Recording, Data Logging, and Process Control - Consolidated or Separate Devices?

Yokogawa CX2000 Integrated Controller and Data Acquisition Device
Integrated  Controller and Data Acquisition Device
Courtesy Yokogawa
Are you a designer or builder of process control systems? Selecting hardware and componentry to provide the functionality, accuracy, and accessibility required to meet process or equipment performance demands can pose some very distinct challenges. When faced with a scope of work that includes multiple PID control loops, data recording, and networking, do you tend to favor using a collection of separate devices for each function, or a consolidated unit that integrates all of the needed functions?

I have designed many control systems throughout my career, and tended toward using separate devices initially. As I gained experience and the feedback that comes from having units in the field for a number of years, my thinking changed and my preference for integrated "single box" solutions began to predominate.

Some reasons to use a consolidated device:

  • Likely to take up less panel space than a combination of individual devices.
  • Substantially reduced wiring, cabling.
  • No tasks associated with getting individual devices to work together, if that is needed. The integrated unit comes out of the box with all of that already accomplished.
  • Reduced parts count.
  • Simplified panel wiring plan.
  • A single HMI encompassing all the provided functions.
  • Anyone, end users, service techs, trainers, quality control, that needs to learn about the operation of the system has a single instruction manual to review or learn. Since the functions all come in one unit, there is often some streamlining to the learning process.
  • OEMs may be able to use a single component to provide the necessary functions for numerous product versions, bringing measurable time savings throughout the product design, fabrication, and support functions of their organization.
  • If spares are required, there is only one.
I have enjoyed good results employing devices that combine numerous functions into a single package. There is a data sheet below, so you can see more about an industrial control, recording, networking device that packs a useful range of functions into a compact unit. 

On your next process control project, consider whether going consolidated or discrete is better for your needs. Talk to a process controls expert and get some additional input. Good solutions are out there.