Ignition Taking it to the Edge
As Ignition evolves, the landscape of their non-fully blown gateways has changed. There used to be a focus on single or reduced client licenses for small systems. These still exist, however with the Ignition Edge packages they are much less common. With the push for hardware companies to participate in Ignition On-Board program, Edge is becoming even more prevalent.
Learn more about Ignition On-Board and check out our unboxing of FreeWave ZumLink radios.
This leads to some common questions. We’re going to cover a few of the common ones here, and all of the details are available in the documentation.
1. Panel vs. MQTT vs. Enterprise
The first question we get is what package should I use? This is easy. Think of each Edge license as a module and you are on the right track. In fact they are termed “plug-ins” in the documentation.
If you want to have an HMI client, you want Edge Panel.
If you want to sync data to a central gateway, or handle anything you would normally use the Enterprise Administration Module for, you want Edge Enterprise.
If you want to use Ignition Edge as part of an MQTT strategy you want Edge MQTT.
You can mix and match the plug-ins to get the functionality you need. As an example Panel plus Enterprise is great for local failover at the machine level, including store and forward capability. Adding MQTT would give you the ability to use this gateway as part of an overall MQTT architecture.
2. Can I use Ignition Edge in a large facility?
Yes. You don’t need to have a distributed architecture like an oil field to use Edge licensing. Our most common use case is installing Edge on the plant floor at each machine with an HMI. We set it up with Panel and Enterprise and use the Edge license for local fallback. If the network goes down, both redundant gateways are unavailable, and you still need to run your plant, you are covered here.
Looking to use Ignition Edge as part of a Digital Transformation? Look at how we are migrating data from old systems to new systems.
3. What about the limitations?
Edge does have some limitations compared to a full Ignition gateway. We haven’t found anything to be a show stopper. Your use case might require something that is a limitation, however we have found with a couple uses of built-in system functions just about anything can be worked around if needed. Most times it makes better cost sense to use a full gateway as part of the architecture rather than writing and maintaining custom code, but people make interesting decisions sometimes.
Here are the major differences:
Not a big issue, if you are using an Edge License you are not looking to run an entire facility on it, so not having multiple projects doesn’t get in the way.
This one can be a bit of a hurdle depending on your use case. If you absolutely must have database access you can most easily use the built-in system.net functions and call an external web-server that will handle inserting records into a database. Most systems we run into requiring database access are okay to be run in a limited mode if we are running on the Edge licenses in the first place. You still get a week of historical tag data, and using the Enterprise license you can sync this with the master gateway, so the most important data will be available.
Gateway level scripts simply don’t exist in Ignition Edge. If you have them, you can simply move everything into Client level script and be on your way. We advocate not using tag event scripts anyway, so the transition should be an easy one when moving from full gateway to the Edge mindset.
The built-in Ignition OPC-UA Server is only capable of acting as a client. Similar to the single project model, this is not something that would usually cause an issue for you if you are looking at Edge gateways in the first place.
4. Where would I use an Edge gateway?
Our most common use case is to run Edge as a cost effective way to keep a plant running when things go absolutely haywire. We also see it a lot in heavily distributed architectures leveraging MQTT. It takes the best of what Ignition has to offer, bundles it at a palatable price point, and is flexible enough to meet the demands of most applications.
Another common task is using the Edge gateway to push data into a master gateway. This is helpful when the Edge gateway is at a remote site with limited connectivity. You can store the data locally, push it up to the main gateway when you have service, and go back offline until you can get connected again. This is great for remote pump stations for a water treatment facility for example.
Want to see more Ignition 8 and Perspective? Check out the Rolling Updates post.