It’s not broken, why fix it?

by | Sep 6, 2016 | Blog | 0 comments

Blog post by Keith Mandachit, Senior Engineer

Keith Mandachit Huffman EngineeringWhen I first started as a controls engineer, the year was 1996.  Allen-Bradley’s flagship Programmable Logic Controller (PLC) then was the PLC-5.  My colleagues and I have implemented many control systems utilizing the PLC-5 that are still alive and ticking today.  One of the reasons it was loved by so many was the PLC-5 platform was extremely reliable.  It was rare for any of the PLC-5 hardware to fail.

As they say, all good things must come to and end.  The PLC-5 family of controllers has been in ‘End of Life’ status for the past few years.  In less than a year, the PLC-5 processors will be officially discontinued by Rockwell Automation in June 2017.  This is the result of a lack of component availability.  The 1771 I/O platform will follow suit at some point.  Are you going to be proactive or reactive?

Why should I upgrade?

The time to modernize and migrate to a new system is now.  The sooner you begin discussions, the better.  But that PLC-5 system is still running perfectly fine.  Why do you need to upgrade it now?

  1.  Once your spares are used up, you will be left searching for parts from eBay or other 3rd party companies.  Do you really want your control system relying on refurbished parts?  If your control system goes down, you will lose production time.
  2.  Better communication options.  The other day I mentioned ‘blue hose’ to a younger co-worker who then stopped and asked me if meant to say Bluetooth.  Data Highway and Remote I/O over blue hose have been replaced by various protocols over Ethernet networks.  While we at Huffman Engineering do have the tools and experience to troubleshoot and support old communication protocols, it is becoming more and more difficult to find people that can, let alone people that even know what you are talking about.

What are my upgrade options?

  1.  Complete replacement.  The entire PLC-5 system including the processor, rack, power supply and I/O modules will be replaced.  The field wiring can be kept and reused.
  2.  Swing arm migration kit.  An adapter kit allows the swing arm from the PLC-5 system to be reused with a new ControlLogix platform.  It’s designed to mount on the same holes from the previous hardware.

Are you thinking to yourself that to upgrade your PLC-5 system is going to be a huge ordeal and going to result in significant downtime?  My colleagues and I at Huffman Engineering Inc. can help you upgrade your PLC-5 system with minimal impact on production and a quick turnaround.  Has the documentation and drawings for your PLC-5 system disappeared or become inaccurate?  An additional benefit of upgrading is that your documentation will be up to date at the end of the process.  Don’t get caught being one of those that wished they would have upgraded sooner.  Be proactive and get the upgrade process started.  Huffman Engineering can help you plan and budget the upgrade.

Feel free to contact me  if you’d like to learn more about fixing that legacy PLC-5 system that isn’t broken yet.