Liquid Coatings Q&A: How to Effectively Use PLCs

Q. What are some of the most effective uses of programmable logic controllers in a coating operation?

A. Using a programmable logic controller (PLC)-based control scheme enables maximum flexibility of current and future design considerations. Instead of re-wiring an entire control panel, simple programming modifications can be made to change how the booth operates.

On larger projects, remote input-output can save installation costs by reducing the amount of field wiring needed. Using a PLC to control a booth can also increase the safety because when properly programmed, a PLC can detect when a sensor or limit switch has been bypassed.

By developing intelligent programming, and combining a PLC with a touchscreen HMI (human machine interface), the control panel can become a training tool for new operators. User-intuitive menus with photos and step by step instructions can be programmed into the system to help new operators or maintenance team members learn how to properly operate and maintain the booth.

A PLC can also be used to record useful information such as how long a fan has been running, filter static pressure, booth temperature and humidity. This data can then be exported onto a flash drive and stored for future reference. Communication is becoming increasingly important with the introduction of IoT (internet of things). When a touchscreen is combined with a PLC, simply connect an Ethernet cable to the system to enable remote monitoring and control.  

 

Steve Houston is the chief marketing officer at Col-Met Engineered Finishing Solutions. Visit colmetsb.com or call 972-772-1919.
 

Bryan Willis, director of controls for Col-Met Engineered Finishing Solutions, also contributed to this article.

 

Originally published in the June 2016 issue.