Perhaps I can't search well, but I'm not finding any information about the data limit for tags. I'm looking specifically for the character limit of a string tag.
Here's my scenario. I want to provide operators with an area to leave persistent notes on site-specific overview pages with a dedicated notes tab, but I don't know what the best approach to this would be. My first thought is to use a string tag to contain any notes and that can then be pushed into the historian for easy retrieval. I'm looking for community input into the best approach to solve this problem. Thank you!
It's probably not a good plan anyway.
Retrieval will probably not be easy.
Have a look at how the Power Chart component saves annotations in, I think, the sqlth_annotations table that is automatically added when you create the first annotation on a Power Chart. To set it up just run a Power Chart in Designer and annotate it. The resultant table doesn't get partitioned (monthly or whatever) so you won't have to worry about that either - unless you think it may grow to large and require a purge of old records (which could be done on a scheduled gateway script).
I'm pretty sure a Power Chart is not the way to go for the solution I'm trying to offer. I'm basically looking to have a virtual whiteboard (no drawings, obviously).
I'm not proposing that you use Power Chart. I'm proposing that you use a similar database table structure for your application. You'll want the t_stamp, userId, processId(?), username, etc., and it would be a mess trying to correlate these in Historian.
I see. True. It looks like Edward was trying to do something similar to what I'm trying to accomplish in this post, but no specifics were shared on his solution. Any thoughts?
It sounds like you're developing a business application rather than a SCADA application so Historian is the wrong tool for the job. Ignition, on the other hand is well capable of doing the business application. Inductive Automation use Ignition in-house for many such applications. See their How Inductive Automation Uses Ignition | Inductive Automation case study.
I've done some for tracking engineering IP address assignment, an engineering password manager, etc.