Tags & Watchlist

The Data Browser lets you explore the tag namespace of your connected PLC and build a watchlist of values to monitor in real time.

Tag tree

The left panel shows the PLC’s complete tag tree — the same structure you see in the TIA Portal Watch and Force Tables. Tags are organized hierarchically:

• PLC tags — global DB variables and standard PLC tags (e.g. I0.0, Q0.0, MW100)
• Data blocks — individual DB entries (e.g. "ProcessData".Temperature)
• HMI connections — if the CPU exposes HMI variables via the WebServer

Click any folder to expand it. Click a tag name to add it to the Watchlist.

Watchlist

The watchlist is a persistent collection of tags you want to monitor. It survives app restarts — your watchlist is stored locally and automatically reloaded the next time you connect to the same PLC.

Adding tags

• Click a tag in the tag tree to add it to the watchlist.
• Or type a tag address directly in the watchlist search bar if you know the exact address.

Removing tags

• Click the × button at desired row to remove it.
• Click Clear all to remove all rows.

Live values

While connected, watchlist values refresh when Refresh button is pressed. When Auto button is toggled, refresh is automatic on a 2-second poll interval.

Column	Description
Name	Tag name as returned by the PLC
Type	Data type (BOOL, INT, REAL, TIME, STRING, etc.)
Value	Current value
Quality	Good or Bad — indicates whether the PLC could read the value
Last Read	Last read value timestamp

Reading tags with the AI Agent

The AI Agent can read individual tag values via its get_tag_value tool and list available tags with browse_tags. This lets you ask questions like:

“What is the current value of ‘ProcessData’.Temperature?” “List all BOOL tags in the ‘AlarmStatus’ data block.”

See AI Agent Tools Reference for the full list of available tools.