I was somewhat shocked at the Emerson Global Users Exchange a few weeks ago to see a booth with several well-known OPC suppliers–but it wasn’t the OPC booth. They were touting a new communication protocol called “Xi” for Express Interface. It was briefly explained to me as an OPC UA “lite.”
OPC UA is the new protocol, kind of long coming out, where the OPC Foundation is taking its well-used protocol suite and moving it from a Microsoft-centric COM/DCOM foundation to a more contemporary and open XML standard. OPC is used in many applications for moving data from the control layer to the manufacturing software layer, e.g. HMI/SCADA and MES. The new UA standard builds on the relatively simple previous version by adding many new functions to enable enterprise software connectivity.
Trouble is, some suppliers really don’t want all that overhead. They want something simple and quick. So a bit of a battle began over whether to release UA at the simpler level of OPC DA or whether to wait until the full blown spec gets done. Emerson Process Management didn’t want to wait–and it wanted the simpler version. So it developed Xi. It brought in partners. I was told by Emerson executives that they would gladly give it to OPC Foundation in order to expedite the process of having this lighter spec. On the other hand, Xi is Microsoft-centric again, built upon dot Net.
Things are progressing. OPC Foundation President Tom Burke reports in his blog about negotiations to bring the spec to the Foundation. Interestingly, Eric Murphy of the OPC Exchange blog by Matrikon wrote a detailed post about Xi. I received it via RSS feed, but when I clicked the link to go to the Web page to copy into this post–poof, it was gone. Too bad. It was a nicely reasoned piece.
Anyway, watch for this Xi spec to simplify and speed up a certain level of connectivity. But if you want further connectivity, press your supplier to get the entire UA implementation done.
Gary & All:
As always Gary does an excellent job communicating about important things in our industry. Currently the OPC Foundation is working on the transition plans to add a very important extension to the existing OPC Foundation portfolio that is called eXpress Interface(Xi). There is a lot of good information about this already on the http://www.expressinterface.com website, including a white paper, podcast, great overview with dive into the details information, and a whole set of downloads that allows suppliers to get a good jump start on actually developing products based on the technology.
The concept is really kind of a middle ground between existing classic OPC (based on Microsoft COM/DCOM) technology and OPC UA. Many of our vendors had added logical extensions to existing OPC COM -based products to incorporate enhancements in security and reliability. Many of our vendors actually have products that have been very successful in the marketplace with these logical extensions. It was apparent the need to standardize on these logical extensions, and an effort to standardize and develop a Microsoft centric solution based on the WCF technology was developed by a number of the OPC Foundation members. The fact that vendors were able to come to consensus and collaborate together, follows the model of the OPC Foundation collaboration since the beginning of time. (Going back in history this is exactly how the OPC Foundation started when four vendors partnered together to develop the first OPC data access specification). Once a demonstration and proof of concept of the multivendor work showing the feasibility of the technology was successful, then came the time to actually standardize on this and add it to the OPC Foundation portfolio.
For those of you that may have heard of Xi before, it actually was being developed underneath the OPC Foundation umbrella as a sanctioned working group. The OPC Board of Directors acted on the recommendation of the Technical Advisory Council to not continue the work as part of OPC, recognizing that the initiative would be further flushed out through an independent effort by multiple vendors, and later reviewed by the OPC Foundation, for possible incorporation into the OPC Foundation portfolio of deliverables.
A press release, and a lot of marketing collateral that will clearly identify the value proposition for the end-users and vendors with respect to all the OPC Foundation deliverables is actively being developed.
OPC has many opportunities for partnership and collaboration with vendors and other consortiums and the OPC Foundation always does due diligence with the standard rule being applied how does this partnership/collaboration benefit the 400+ members of the OPC Foundation. OPC is not in the business of developing specifications for the sake of developing specifications. OPC is all about developing specifications, technology and process where success is measured by the level of adoption of the respective technology. We don’t do single vendor solutions. We develop technology that allows a multitude of our members to be able to adopt the technology into real products solving problems that are end-users want. The Xi technology has been developed over the last six months, with a focus scope of solving the problems that are end-users have on existing Microsoft platforms with security and reliability. The business case to add this new technology to the OPC Foundation portfolio was evaluated, and it passes the test of technology that our vendors want to adopt into real products.
This addition to the OPC Foundation portfolio, is a logical extension expanding the breadth of specifications and technologically for secure reliable interoperability. OPC UA is focused at addressing complex information model, the embedded market, and platform independence, and it is really positioned to be the equivalent of providing the interoperability that are end-users and suppliers come to expect in consumer electronics, and doing the same thing done in the consumer electronics world for factory automation and process control. So when you’re looking for OPC on an iPhone, OPC UA is clearly the technology that will be used for the products on the iPhone devices (this is one small example of the sky is the limit applications).
Thanks again Gary for introducing the topic and doing a great job on giving me the opportunity to do a lead in on where the OPC Foundation vision is going.