Tags

How THMI represents the individual data points collected from your equipment.

A tag is a single data point collected from your equipment — for example a temperature reading, a pump’s running status, a setpoint, or an energy meter value. Tags are the foundation of THMI: nearly everything else is built on top of them.

Each tag has a current value that updates as new data arrives, and its history is kept so you can look back over time.

What tags are used for

Once a tag exists, you can:

• See its live value on a page or in a list.
• Chart it over time with trends.
• Watch it with an alarm, so you’re alerted when it goes out of range or a device stops responding. See Alarms.
• Act on it, where a tag is writable — for example adjusting a setpoint.

Where tags come from

Tags represent data read from real devices in your building — controllers, meters, and sensors. THMI talks to these devices using the common building and industrial protocols (such as Modbus, BACnet, OPC UA, M-Bus, MQTT, and TwinCAT), and each value it reads becomes a tag.

Some tags aren’t read directly from a device but are calculated from other tags — for instance combining or transforming values — so you can work with the numbers that matter to you.