Now that ignition 8.3 supports storing tags in JSO, I’m wondering if there exists a JSON schema or some other type of schema for all tags?
Would be helpful for writing tags to a JSON file and validating the structure is correct.
No, but a running gateway maintains a tag model for each tag provider that can be interrogated with SDK API methods from jython.
Making a formal schema would be difficult, as various Ignition modules, including 3rd party modules, add to the tag property model as needed for the features they provide.
This tag property model is interrogated as needed by the designer to make the designer's tag editor suitably dynamic.
You can find some core examples in the Exchange, in the "Tag Report Utility" project's scripts.
You can use JSON for tags in 8.1 also. One of the primary ways I migrate tags from legacy systems to Ignition is to dump an export of the tags into a database and write a script transform that outputs JSON. Then you just copy/paste that into the tag browser and you have tags.
I’m not aware of any documentation of the schema. I just made a tag with min/max bounds, an alarm definition, etc to have examples of all the things I might have on a tag. Then I selected the tag and copied as JSON. I paste that into notepad and use it an the example of the schema. The rest is just making a script transform that parses the data and builds the JSON for the tags.
I’d recommend copy/pasting tags made in this way into a folder so you know which tags are new. Here’s an example video. The reason the tags don’t resolve is that I don’t have a topic configured for a test environment. I’m just showing an example so you know which part to copy to end up with tags. If you copy the wrong node it won’t make tags.