Hi all,
I'm trying to integrate Ignition's OPC UA server with FactoryTalk View v13. I managed to work through the certificate trust issues using Security Policy setting: None,Basic256Sha256. And I have successfully read Ignition tags through FactoryTalk Live Data for a couple minutes before the connector crashes. The root of the problem, that I fear will never be fixed, is a bug that was documented by Rockwell at least two years ago.
Rockwell's OPC UA Connector runs out of memory while enumerating tags because it doesn't handle tag properties and hints correctly. I only have around 1100 tags but the FactoryTalk connector crashes with an out-of-memory error after reaching 286K tags.
Kepware and ThingWorx, apparently, have compatibility options to workaround this bug.
From FactoryTalk Linx OPC UA Connector v6.40.00 Release Notes...
When utilizing the OPC UA Connector to interface with PTC’s Kepware or ThingWorx software, the settings Return Tag Properties and Return Tag Hints
of Kepserver will affect the number of tags that are exposed when a client is connected and browsing. When these settings are enabled, the number of tags
is excessively large and could cause FactoryTalk Linx OPC UA Connector to stop responding or shut down.
To work around this problem, the settings Return Tag Properties and Return Tag Hints of Kepserver should be set to No by default.
Does Ignition have similar settings? If not, may I suggest that as a compatibility feature?
Thanks
No, it doesn't have similar settings, and these aren't terms used in OPC UA so I don't even know what they mean by it. Do you have any additional information?
How many tags do you have defined in Ignition? Is the Exposed Tags feature enabled? How many devices do you have connected to Ignition's OPC UA server?
It sounds like Linx is doing a full recursive browse of the address space of any server you connect it to?
Thanks for the quick response.
Not sure on their terminology... I'll attach a PDF of an article from their knowledgebase, if that helps.
FactoryTalk Linx OPC UA Connector hangs at starting.pdf (287.4 KB)
I think you're correct about it being in a recursive loop. I have 1154 tags and 5 ControlLogix devices. I did expose the tags - that's actually the part I'm interested in. We use SQL Bridge for data entry, but often there isn't a compelling reason to create tags in the PLC since they won't be used by it.
Their connector is probably trying to browse all of your connected ControlLogix devices in addition to whatever tags you have defined in Ignition and are exposing.
I can't think of any way to work around this right now. Their connector is plainly broken.
In 8.3 there will be a Roles and Permissions implementation that would allow you to give credentials to 3rd party clients that only had access to certain tag providers and certain devices, while the ones they don't have access to will be invisible during browsing as well. Doesn't help you out now... but some day.
I did check if I could block it to just Tag Providers using permissions, but no luck. Cool that it's on the roadmap, I'll be on the watch for that feature. Until then, I'll keep using PLC tags. Thanks for your help Kevin!
I'm going to be at an OPC event in a couple weeks and I think one of the Rockwell guys who works on this connector will be there... I'll ask him if there's any work around or fix planned.