A Tag binding simply binds a property directly to a Tag.

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[00:00] In order to create HMI screens, or real time status and control screens in Ignition, we have to be able to link components to various tags in the system. And we can use property binding to make that happen. So here for example in my designer, I have quite a few tags I've already created in my tag browser. I can take any component in Ignition and I can link it to any tag. So let's say for example I take a meter component from my display tab, put it onto the window. I can link any property of the meter to any tag. Most important property here is the value property, so I'm going to go to the value property, click on the binding buttons at right hand side, I'm going to link it to a tag, selecting the tag binding type. I'm going to go expand my tags and find any tag in the system. This case I'm going to go down to N7:0, and just simply come down and press OK, and you'll see that it is linked now to the tag. As the tag value changes, of course my meter is going to reflect that change. It's also important to note that the property is bold, letting me know there's binding on it. If I look up here in the project browser on the meter component, you're going to see a little tag icon to the right hand side, letting me know that some property is linked to a tag. I can do this for any component. Let's say for example I take an LED display and put it onto the window. I can bind the value of the LED display directly to a tag, and this time, I can select N7:1. So we can link any property in Ignition to any tags, they're a very simple binding type. Now there's one catch on the binding that's really important to note. In that the binding is actually linked directly to the tag path of N7/N7:1 here, for example. If I go and rename that tag, or move that tag somewhere else, the binding here will actually break, because it will no longer find that tag. So we don't link directly to a tag, we link it to a tag path. So if I go over here to N7:1 and I right click and rename this to say temp, you're going to see that the LED display now is showing an overlay that's saying "tag not found", and if I go back into the binding, it's also going to tell me that I cannot find the tag for that path anymore. I can go back in here and I can update it to select temp, as now it's N7/temp, and press OK, Of course, now it's okay. But Ignition will not automatically change that tag path for you because it's a string path. So it's really important to get your tag database kind of set up ahead of time and after you do all your bindings you really want to kind of leave it alone.

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