XML interface

I have been setting up PMI projects knowing that the OPC interface to facility equipment is going to go away in favor of web service for buildings. Well the time is coming closer. One of my clients wants to move his system from the older Johnson Controls OPC server to a web based XML server.

Do you have recommendations or testing done on any interfaces or methods to get XML data feeds.

Hi Darrel-

Currently we don’t know of an OPC server that reads from XML services, though one may exist.

However, this is also not the first time someone has posed this question to us. We have been considering a few options for working some solution into FactorySQL, but we haven’t made a decision yet.

Perhaps you could give us a little more information about how the service works, the format of the data, etc. Feel free to send it to support AT inductiveautomation.com if you don’t want to post it.

Also, just to clear up one thing, it’s not by chance using the OPC XML standard for the service is it? The opc foundation had defined a format for webservices, but I’m not sure that many vendors implemented it. However, a quick search showed that it may be more popular in building automation.


It’s my understanding that OPC UA will be web services based. Tom Burke from the OPC Foundation left a comment on my blog that emphasized his priority on backward compatibility.

Also, FactoryPMI works with SQL databases (including SQLTags) and has no “direct” notion of your PLCs. This de-coupling should work in your favor in terms of selecting a migration path as PLC communication supports a more modern interface.

blogger.com/comment.g?blogI … 4725886370

Yes, UA is “web-serviced based”, but that doesn’t help much with proprietary web serviced based system. It’s kind of like saying two people can communicate because one person can talk and one can hear- not much good if they’re speaking different languages!

Basically, UA is going to be the standard for doing what Darrel needs to now with this particular vendor. Let’s hope UA can get up and running before too many vendors solidify their positions with their own solutions!

Just some thoughts,