In the last year, we have probably all worked remotely from our control system equipment more than in previous years.  Putting our eyes on our control equipment may have been little or none for many months now.

Maybe you have systems in place for monitoring your control system equipment and maybe you do not, but hopefully this will help you begin to identify places that could be lacking.

Walk it Down

Today we can do almost anything remotely to our control systems. We can troubleshoot, program, configure and monitor systems from miles away in the comfort of our home, however, there is still an imperative need to put our eyes on our systems. We cannot take it for granted that simply because the system doesn’t show a problem, that there is not one.

Here is a scenario for you. You go online with a PLC and everything is fine, controller synchronization with the backup, I/O has no faults and you cannot see any issue with this system.

Image by Brandon Cooper

Upon a walkdown of your control equipment, you observe this: A remote I/O chassis has fallen from its mount on the front of conversion hardware. The only thing holding the I/O rack up is a cable that provides power to the remote chassis and a relay that will shutdown the equipment if it comes loose. This is definitely a problem that a few more days of vibration will bring to a machine shutdown around 3AM this Saturday morning while you would rather be asleep.

Image by Brandon Cooper

Because you took the time and effort to put your eyes on this control system equipment, the problem could be resolved, and the machine will no longer see downtime in the next few days because of lack of awareness of the control system.

Image by Brandon Cooper

I would suggest that checking all your system components physically and visually on a regular schedule is a preventive maintenance measure that absolutely cannot be dismissed during these times of work that may be different than before the pandemic. Following good safety protocols, make this a priority and you will be glad that you did.

Automatic Monitoring

Many times, there are monitoring features that we fail to utilize. Here are a couple:

  • PLC Redundant Power Supply

A redundant Power Supply contains an alarm contact that can be wired to a control system input to monitor that the power supply is functioning without alarm.

Image by Brandon Cooper

  • Secondary Power Source of a Switch

Most industrial switches have the option of using two power sources in case one power source is lost, however, many times we do not install and wire both power sources. And don’t forget to check on the switch regularly and see that both power sources are available. There is also an alarm contact here that can be wired in as well for remote alarming.

Image by Brandon Cooper


The list here could go on for miles of examples of things that need to be monitored. The status display on your servers and workstations, the lights on your network cards and network equipment, physical mounting of hardware and I/O modules, making sure cabinet doors are closed and facilities are clean, making sure cabinet cooling fans are running and filters are clean.

These types of checks will make us world class or cost us production, the choice is up to us as to which road we take.

Written by Brandon Cooper
Senior Controls Engineer and Freelance Writer

Have a question? Join our community of pros to take part in the discussion! You'll also find all of our automation courses at

Sponsor and Advertise: Get your product or service in front of our 75K followers while also supporting independent automation journalism by sponsoring or advertising with us! Learn more in our Media Guide here, or contact us using this form.

Brandon Cooper


Please enter your comment!
Please enter your name here