Dedicated SCADA Tag Provider

Ignition
1

Looking to get some feedback or ideas from people here. Our current Ignition setup revolves around having a set of automation cells, each with their own full Ignition gateway, connected to a central enterprise gateway. Each cell has a tag provider populated with the PLC tags needed to run the cell and populate the HMI. Certain tags have changes stored through the tag historian, split between a tag historian database at the cell gateway and a tag historian database at the enterprise gateway.

The enterprise gateway has a remote tag connection to each cell tag provider, which is used to populate dashboards, historical screens, data analysis, etc.

I'm starting to run into concerns with the number of tags being transmitted over the gateway network. Some of these cells have a large amount of tags (~90k in the worst) that need to be present in the tag provider as they do various functions and need to be visible in the HMI.

So, I'm investigating the possibility of creating a dedicated 'SCADA' tag provider for tags intended for use in the projects at the enterprise level, which would then become the tag provider that the enterprise gateway remotely connects to, which should significantly drop the number of tags that are being transmitted. I'm not exactly sure how this would be setup, whether tags are devoted to each provider, or if the SCADA tags would just be reference tags to the tags in the base provider. Also leads into questions about how the tag history setup would be done, which then ties into populating visuals, and can keep spiraling into other questions.

I'm curious if anyone has a setup that works like this, or if there is a better method of managing the tags that I'm not seeing. Any feedback or thoughts would be appreciated!

2

I would start looking into the Diagnostics / Status section on your enterprise gateway to see what your actual performance is looking like. Don't just go off a gut feeling that 90k tags is too much, look at some actual metrics. Look at the performance, response times, system load, ect to determine if adding a SCADA tag provider is actually worth it for you

3

Tags aren't transmitted through a remote tag provider unless something requests them, or subscribes to them. Are you sure you have a problem?

4

@pturmel @jrusso I have to admit that I don't have a good understanding of how the remote tag providers work. I was under the general assumption that if a tag value changed, then some sort of 'message' would get sent through the gateway network to each gateway that has a remote tag connection.

But it sounds like that's not the case, and that tag values are not 'pushed' but instead 'pulled' when needed. So any screen or script or logic that involves a remote tag would initiate some sort of request or subscription for updates?

How does this work in the context of browsing tags through the designer? Would viewing the tags in the tag browser initiate a subscription?

It sounds like that if the majority of these tags are simply process/data tags that aren't used in visuals or logic at the enterprise level, then it shouldn't have a real impact on performance.

Thanks for the responses

5

Exactly.

In older Ignition, yes. In modern Ignition, no, the designer uses polling. I don't recall exactly when that changed--in the 8.0.x timeframe, I think?