Tags limit for Ignition


I am facing a project where i am going to have a lot of OPC Tags configured, technically speaking around 250000 tags.
Is Ignition having any tags quantity limits?
Do Ignition propose any special setup for high tag density?

There is no arbitrary tag limit. 250,000 is within the realm of what you can do on a single gateway if you use good hardware. The limiting factors may be where the tags are coming from and the rates you need to poll at.

What kinds of devices, how many tags per device, and what update rate do you need?

Ignition’s gateway is very good at parallelization. Extra cores do wonders.

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I am using 1 second update rate, I will be aggregating data from 3 different OPC-UA servers into Ignition as some kind of data aggregation point.

To be honest when i have too many tags it starts having problems when browsing tags or adding/removing tags.

My actual count is around 70.000 tags using different native drivers, like Siemens, TCP or ModBUS.

Actually i have 8 cores and 16Gb of Ram.

This will be relatively easy for Ignition to handle, as the performance burden will largely be on those 3 servers, not the Ignition OPC UA client.

Have you worked with support yet? This is not the largest tag count deployed by a long shot, so maybe there’s something weird about the tag structure or resources or something else that is causing problems.

Hi :slight_smile:

Can I ask what is the biggest number of tags that someone used in their project?
Or at least what is the biggest project you know of?

I’m asking because for our potential use case, there may eventually be over 1 000 000 tags on a single Gateway (some of them OPC, some MQTT), ideally with no more than 5 seconds refresh rate.

Also, is there a way I could get some data/statistics for some big projects?
For example: what kinds of server HW do they need to achieve smooth performance?

Most 1M+ tag systems are done by using multiple Ignition gateways and remote tag providers, but it might be possible to do it all on one depending on where your OPC tags are coming from (external vs internal) and how many are OPC vs MQTT.

You would want something like 6C+ or 8C+ Xeon, 64gb ram with 32gb for Ignition, SSD instead of spinning rust. Probably more than this if you are going to have a heavy database load and run it on the same server, but it’s usually best to run the database on its own server in that case. Don’t use virtualization, run Ignition directly on real hardware. Use Linux if that’s an option.

I’ll try to get someone from sales engineering to chime in as well since they will have some better real world numbers.


Thanks a lot for your fast response & recommendations!!! :sunglasses:

The vast majority of the tags would be external, coming from over a 100 different PLCs.
The plan is to transition everything to MQTT (which should help with the load), but that will be a gradual process over the next few years.

Looking forward to the data from sales.
Once again, thanks a lot!

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What I mean by external is that they are from another OPC server such as Kepware or a PLC that has its own built-in OPC server, rather than being polled by Ignition’s drivers and made available in Ignition’s built-in OPC server.

This would reduce the load on Ignition for sure, but you do realize there is no magic here and that this means all 100+ PLCs either need to natively support MQTT or now have something local to it polling data and then pushing it to an MQTT broker, yeah?

Sorry, I misunderstood - yes, they would be coming from an external OPC server (maybe even servers), running in it’s own VM. (or “on the metal”, if needed)

Yes, I know, but that’s not under my control. The PLCs are managed & upgraded by another department. They just told me that their plan is to upgrade the PLCs gradually over the next few years to transition to MQTT, nothing more specific.

I do think it will be possible to use only 1 powerful Ignition server in this case, then.

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