
I did a little fact checking to find out if there are any PLC controllers available with OPC-UA embedded. As far as I can tell, none are available yet. I found a page for the OPC Technology Summit 2012 which has
downloadable presentations from major automation vendors like Rockwell, Siemens, and ABB. Each laid out their OPC-UA adoption roadmap.
How is it these presentations glow about the wonderful virtues of OPC-UA, yet you can't find a PLC with OPC-UA embedded? (Please tell me if I'm wrong, I hope I am.) There's certainly no technological barrier preventing it. There are many OPC-UA development tools available from companies like
Prosys OPC and
OPC Labs.
Embedded Labs even provides OPC-UA on a chip that costs less than five dollars.
Adoption Roadmap
But, there is a glimmer of hope. Each of these manufacturers has put embedded OPC-UA on their adoption roadmap. They say they are going to do it, but not one has said when. This is especially interesting when you consider Inductive Automation and most other pure software companies have had OPC-UA for years now. Works great.
So what's so special about OPC-UA? Secure, simple, cross platform, flexible, standardized. Enough said?
Imagine OPC-UA Everywhere
Imagine a world of 100% OPC-UA. Gets me all excited because it would take the pain out the subject of intercommunication, between devices, between enterprise applications, and between devices and enterprise applications. For example, from the Ignition server running right here on my desktop I can connect to any number of other Ignition servers running on other people's machines in just minutes. And I can connect to
Kepware servers running on other machines with similar ease. Now if I only had a few OPC-UA-enabled PLCs to connect to, the world would be beautiful. I won't hold my breath.
Sadly, when I mention this beautiful vision people usually roll their eyes and sigh a wistful sigh. (Try it sometime, it's true.) They know it should be but there's a tacit reality that even though it would be right for end-users and integrators, there's little incentive for PLC vendors to be more open.
Security as an Incentive
However, there's a good reason for hardware vendors to adopt OPC-UA that has nothing to do with openness. It is the one thing they are being beaten up about and that's security. OPC-UA is very, very secure and that solves a lot of their problems. It has built-in encryption and can use certificates to ensure end-points are who they say they are. We wrote our OPC-UA client and server from the ground up (from the specification) which was no easy feat mainly because of all the security involved. And speaking of that, anyone who attempts to create proprietary security schemes based on secrecy is going to be the least secure of all. Encryption and security schemes that are exposed to general public scrutiny (like the OPC-UA specification) will be tested and vulnerabilities exposed so they can be fixed.
I wrote this post because I thought it would be fun to imagine what it would be like if the anarchy of endless communication protocols was gone and we could experience the simple, secure, and standardized beauty of OPC-UA to communicate between all devices and software applications.