Many selection and programming concepts used for PLCs/PACs still apply for modern edge controllers, but users should embrace some new strategies and tools to take complete advantage of the possibilities.
My article in the May/Jun 2022 issue of InTech, titled Future-Proofing Controls Programming for the Edge, looks at how modern architectures can support the best of traditional control and modern edge solutions.
Edge entranceAutomation systems have evolved from hardwired relays to PLCs to PACs, and now to edge controllers. “Edge computing” and “digital transformation” aren’t just theories, they are already being deployed to provide improved visibility, create analytical insights, and even autonomously initiate responses. While not every end user is ready to completely embrace all edge automation capabilities, it is possible to architect designs by building upon past concepts so they are future-proof and ready to move forward when the time is right.
Programming evolvedClassic PLCs were programmed using ladder diagram, which was sufficient for basic operational technology (OT) control. As computing capabilities progressed, other languages like structured text arose to take advantage of complex math and more. Now edge controllers are mainstream and need to support information technology (IT) computing using languages like C++ and Python, so industrial automation programming is evolving again.
Edge design conceptsSome users may develop edge solutions using an ad-hoc variety of hardware, software, and programming, but this introduces risk and complicates testing and support efforts. A better approach is to work with an established industry vendor like Emerson, with deep experience in all aspects of industrial automation and a large portfolio of coordinated products.
For example, Emerson edge controllers interoperate with existing PLCs/PACs and provide user benefits like:
A true edge evolutionMany suppliers claim to offer edge controllers, but Emerson provides the most rigorous implementation by using hardware virtualization to ensure that real-time and general-purpose computing run independently and cooperatively.
The edge controller can simply be used as a PLC/PAC—even running code developed for one of those platforms—for a control application.
Or it can be used as a general-purpose edge computing platform running any number of apps.
But many applications will provide exceptional results if an edge controller is used for control and computing, to seamlessly combine OT “inner loop” and IT “outer loop” solutions.
Edge controllers represent an exponential capability increase over traditional PLCs and PACs, so it makes sense that even more languages and applications are being added. This does not mean end users need to discard their experience or embrace all the added capabilities at once.