I've got a project I'm working on for a customer that has a 3rd party modeling software that will be communicating with the PLC.
Currently this modeling software is communicating with the existing controller, DCS, via OPCDA. We are replacing the DCS with Rockwell GuardLOGIX PLCs etc...
I'd like to explore the options for OPC-UA through Ignition. I'm not sure that the vendor can even do OPC-UA, however before I go to deep into that part of the problem, I'd like to understand the capabilities of the Ignition side so I can talk semi-intelligently.
The system we are deploying to site is based on the scale-out architecture. With redundant front ends, and redundant back ends.
Does the OPC-UA side of things, and I'm not real familiar with the nuts and bolts so I apologize in advance, handle the redundancy of the gateways? IE can the 3rd party system connect to the back end gateway and if the primary goes down, will it automagically roll over to the backup? Is this handled by Ignition or is this something that the 3rd party software needs to handle?
I'm trying to stay away from having a one off FTLinx OPC DA server hammering my PLC when the data that is already needed is in Ignition.
It will have to make connections to both gateways.
IIRC, there's a special node ID that can be interrogated for active/backup roles, but I don't know what version it appears in.
It's something the third party needs to handle.
Ignition's OPC UA server, when running as part of a redundant pair of Ignition Gateways, implements what's called "Non-transparent Redundnacy" in OPC UA, at RedundancyLevel Cold.
This means the client needs to be aware and monitor the ServiceLevel / connection status and switch to the backup when the primary goes down.
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Thanks! Is this something that is special to Ignition or is this something that is typical with OPC-UA?
I'm having a meeting with this 3rd party contractor, and I want to make sure I have at least a basic understanding.
It is completely possible that they can't even do OPC-UA. If they can't do OPC-UA and must do OPC-DA, do you know of a bridge from OPC-UA to OPC-DA that can handle this change over?
Typical, defined by the OPC UA spec.
No, but maybe Kepware? It can be an OPC Classic server and it can make OPC UA connections... so maybe you can make that work?
Nobody is making dedicated gateways going that direction.
Thanks for the help.
I'm at least armed with enough to be dangerous.
It looks like UA and Cogent make "gateways"?
https://cogentdatahub.com/products/datahub-opc-gateway/
Any experience with either of these with redundant gateways?
Oh cool, didn't realize they went both directions.