What a tag is

A tag is a named value. It has a path such as Press1.PartCount and, when asked, returns three things at once:

	Meaning
Value	the number, the text, the object
Timestamp	what the value is as of — not when you asked
Quality	whether the value is usable (see Tag states)

The three always travel together. A number without its quality is a guess, and a value without its timestamp does not say whether it is from just now or from the day before yesterday.

Why tags exist

Tags are the only route by which data reaches the interface. A widget, a mask, a script and the AI all ask the same tag; none of them talks to the database.

There is a practical reason. Where a value comes from is the tag’s business: today a query over your operational data, tomorrow an MQTT topic. When you change the source you change the tag — and nothing that points at it has to be touched. The other way round would mean reworking every dashboard one by one.

Path and identity

The path is the name you call a tag by. It is changeable. A tag’s identity is an immutable id behind it, and everything that points at a tag points at that id. Hence: Renaming changes the path, never the identity - everything that refers to it follows. More under Tag paths.

What you set on a tag

The tag page under Settings › Tags is divided into four sections: Identity, Source, Parameters and Behavior. These entries exist on every tag, whatever its kind:

Label	For
Tag	the path
Origin	the kind of tag — fixed when it is created (see The six tag kinds)
Description	What this tag is for
Unit	pcs/h, bar, °C — without it, 1483 is not an answer
Active	whether the tag takes part
Reach	how widely its value is shared — derived, not entered (see Bindings)

Below the value sits an area with three tabs: Used by (who reads or writes here), History and Bindings.

History: what is kept

TrakState holds one current value per tag. The History tab shows a short window of the values that arrived most recently; it begins at the last restart and lives in memory, not on disk.

For tags that work their value out on read, the history is empty, and the page says why: A tag of this kind can have no history: its value is worked out afresh every time it is read, and nothing is kept. A time series over long periods is built with a query tag over your operational data, where the data already lives.

Who may do what

Writing values is open to every normal role. Creating and changing tags is configuration and stays with the tenant administrator. The setter defines the tags; the shop floor and its machines fill them.

The tag list re-reads at most once a second

The list under Settings > Tags shows the current value of every tag. It listens to the same signals a board does - and in a plant where several machines report every second, so many arrived that the page kept fetching the whole value map again.

Since September 2026 it collects those signals: at most one re-read per second, and the last signal is never lost - it is fetched as soon as the second is up. Nothing visible changes except the load: values still follow along, just not a hundred times a minute for the same second.

What this is not: a deadband. No value is skipped and none is smoothed; the question is simply asked less often. What stands on a tag is still exactly what was written to it last.

Objects from a template

A template from the store (Settings › Templates) creates tags under a namespace of its own, for example OEE.Line1.Output. Such tags carry a badge “from