[00:00] When there's a problem with one of your tags, sometimes it requires a bit of detective work to find the source of the issue. The tag diagnostics window is usually a good place to start. Here in the tag browser, I have a tag that's clearly got a problem. If we hover over the value showing in red, it'll give us a helpful tooltip message about the error it's currently showing. I want to look at the tag diagnostics window to see if we can figure out why it's throwing that error. There are two different ways to access tag diagnostics within the designer. If you just want to focus on the diagnostics, you can right click on the tag you want to examine, and select View Tag Diagnostics. A separate popup window will appear that lets you look specifically at the tag diagnostics, any active subscriptions, and the reference log. There is another option for accessing tag diagnostics that may give you a little more context as well. I'll close out this window and we can see that method.

[01:05] Depending on your needs, you may want to look at other information within the tag editor first and then check out the tag diagnostics. In that case, you could double-click on the tag to open the tag editor and then look for this icon in the header menu. The same tag diagnostics window opens from that location as well. In the diagnostics tab, we can see the current value, quality, timestamp information, and some initial error messages for the selected tag. This window displays a snapshot of the information that was collected when we opened the window. If you'd like to update the information while you're in the tag diagnostics window, you can use this refresh button here. The second tab, active subscriptions, displays real-time tracking of a tag subscription. Here, under the subscriptions column, you can see the path to a resource that's currently subscribed to the selected tag telling us where it's being used in Ignition. If you expand that path, you can see additional information about that subscription.

[02:05] In this case, you can see I've bound this tag to the LED display in my new Perspective view. The first referenced column can tell us when the tag subscription was created, and the totals column gives us the number of currently active subscriptions from the reference location. If I had multiple Perspective sessions with the same view bound to my Sine0 tag, this number would go up. There are also several buttons in our toolbars here that can help us expand and collapse how much information is displayed for better focus, or, if we want a more updated view, we can refresh our results. In addition, the designer button is available to show or hide references to the specified tag from the designer, including in the tag browser and vision components when in preview mode. The reference log tab displays the data from the tag reference tracker store as a way to find where tags are being used in a project. Since we'll go into more detail about the reference log and tag reference tracker store in future videos, this tab's functionality will become clear in those lessons.

[03:09] For more details about the tag diagnostics window, the reference log tab and the tag reference tracker, please see the Ignition User Manual links below this video. Now, let's go back to our diagnostics tab and see if we can figure out what's gone wrong with our tag based on what we see here. For the last published value, we're showing a null and error_configuration. So, to get a little more information, let's take a look at this OPC area, which I can expand. As you start adding additional configurations to your tags for things like alarms, you'll start to see new areas under tag diagnostics that you can expand and get more information about. So the last subscription value is also returning a null value and error_configuration message that says our node doesn't exist in the server address space. On an OPC tag, this generally means that there's a problem with the OPC Item Path.

[04:04] Let's close our tag diagnostics window and go back to the tag browser. I'll double click to open the tag editor and we can see there's a typo in our OPC item path. It should be pointing to Sine0, not Sine10. To fix that, I can either delete the one directly or I can select the browse devices icon and drill down to the correct item path for my tag. I'll click ok, and now the value is coming through as expected. The tag diagnostics window gives us quick access to relevant tag information and metrics that are sure to make any tag-related detective work faster and easier.