Empowering your PLC with IEC 61131-3

Empowering your PLC with IEC 61131-3

Nobody loves catchy numeric buzzwords as much as me. I - E - C - Six - Eleven - Thirty - One - Dash - Three.... It just rolls off the tongue! OK I admit, it's a mouthful, but trust me it's worth knowing about.

This is a brief intro to IEC61131-3 and the first part in a series of posts that will cover its features and benefits. So what is it?

The International Electro Technical Commission (IEC) is a non-profit organization that develops standards for electrical and electronic technologies. They developed and published a standard (IEC 61131) in 1993 for PLCs (Programmable Logic Controllers). Part 3 of the Standard, deals with the actual way that PLCs are programmed, so it's the part that we programmers care the most about.

Prior to the standard, every PLC manufacturer had their own proprietary means of programming their PLCs. Most were based on Ladder Logic but there was not a lot of consistency among platforms.

The IEC created the standard as a means of providing hardware vendors with a powerful, flexible, AND CONSISTENT framework that standardized every aspect of a PLC program. Here are some of the main benefits:

  • Reduced Learning Curve - Programmers that know IEC61131-3 can easily learn any new hardware platform that is based on the standard.
  • Code Portability - Although this is a little more difficult in practice, code can be ported from one hardware platform to another.
  • Powerful Feature Set - There are some powerful features built into the IEC61131-3 framework that allow high level programming which can significantly reduce the time required for implementation, debugging, testing, and code replication.

We are huge fans of the IEC standard because it really empowers us and allows us to maintain our competitive edge. Typically we can program and debug an IEC 61131-3 PLC in half the time it would take to do the same on a non-compliant platform. In our business, (and probably yours too) time is money and we appreciate any technology that enhances our efficiency and effectiveness.

Check out future posts on this topic where I will dive into the details of the IEC 61131-3 standard and explain its many features and benefits.

In the mean time, check out some of these links for more info:

Learn more about DMC's PLC programming services.


Tim Jager
# Tim Jager
I do like a lot of what the IEC 61499 has to offer. We are always looking for better, faster ways of programming, however we have not encountered a PLC implementation of the standard. I think the major PLC manufacturers will have to start adopting/promoting the standard before we see more widespread acceptance.
Aleksi Kopponen
# Aleksi Kopponen
Hi Tim!

How about IEC 16499? Have you been involved with that standard (for distributed control systems)? I have only a few experiences from my M.Sc. studies and I haven't seen any PLC system based on IEC 16499. However, it has some advantages, too!

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