Tag Data View
The Tag Data View lets you browse the raw historical data stored for any tag directly from the Historian browser
Overview
The Tag Data View lets you browse the raw historical data stored for any tag directly from the Historian browser. Click any tag name in the Tag Grid to open a live, scrollable table of Time-Value-Quality (TVQ) records for that tag. You can set a custom time range, enable live auto-refresh, and copy the data to your clipboard for pasting into a spreadsheet.
This is useful for verifying that data is being recorded correctly, inspecting data quality codes, and spot-checking values without writing a query.
How to use the Tag Data View
Opening the view
- Navigate to the Historian at
http://<historian>:4511. - Open a dataset and find the tag you want to inspect in the Tag Grid.
- Click the tag's name. The Tag Data View opens, showing the last 5 minutes of recorded data for that tag.
Setting the time range
The Tag Data View supports two time range modes, toggled with a single control in the page header.
Relative mode (default)
Enter offsets from the current time in the Start and End fields using the relative time syntax:
| Expression | Meaning |
|---|---|
-5m |
5 minutes ago |
-1h |
1 hour ago |
-1d |
1 day ago |
-1w |
1 week ago |
0 or empty |
Now |
h |
Start of the current hour |
d |
Start of the current day (midnight) |
In Live mode, relative expressions re-evaluate on every refresh — so -5m always means 5 minutes ago from the current time.
Fixed mode
Switch to fixed mode to enter specific start and end dates using date and time pickers. When switching from relative to fixed mode, the currently resolved times are pre-populated into the pickers.
Live mode
Toggle Live in the page header to enable auto-refresh. In Live mode, the data grid refreshes approximately every second and shows the most recent data. Changing the time range disables Live mode automatically.
When Live mode is off, use the Refresh button to manually reload data for the current time range.
Reading the data grid
Data is sorted with the most recent timestamp first. Each row shows:
| Column | Description |
|---|---|
| Timestamp | Local time, format: yyyy-MM-dd HH:mm:ss.fff |
| Formatted Value | The value displayed with any unit-of-measure mapping or format string applied |
| Raw Value | The underlying numeric or string value as stored |
| Quality | Numeric quality code, colour-coded (see below) |
| Quality Description | Human-readable quality label |
Quality codes
| Code | Description | Colour |
|---|---|---|
| 192 | Good | Green |
| 28 | Good (local override) | Green |
| 64 | Uncertain | Yellow / amber |
| 0 | Bad | Red |
Copying data to clipboard
Click the Copy button in the page header to copy all currently loaded rows to the clipboard as tab-separated values (TSV). Paste directly into Excel or Google Sheets — each column lands in a separate cell. The first row is a header row.
Troubleshooting
| Symptom | Likely cause | What to do |
|---|---|---|
| Clicking a tag name does not open the Tag Data View | The tag name column is not rendering as a link — may be a browser rendering issue or an older cached version of the Historian UI | Hard-refresh the Historian page (Ctrl+Shift+R or Cmd+Shift+R). Confirm you are running Historian 1.3.2 or later — the Tag Data View was introduced in 1.3.2 |
| The data grid shows no rows even though the tag has data | The selected time range does not cover a period when data was recorded, or the tag has only been collecting data for a short time | Widen the time range. Try -1d to 0 (last 24 hours) as a starting point. Confirm the Collector is actively sending data by checking the Dataset.Writes system tag |
| The Quality column shows red (Bad) values unexpectedly | The data source reported bad quality — the device was offline, the OPC UA node was in error, or the Collector sent quality 0 explicitly | Check the Collector log files and the data source (OPC UA server, MQTT broker) around the time of the bad quality points. Good quality (192) should return once the source recovers |
| Formatted Value and Raw Value show different numbers | A unit-of-measure mapping or format string is applied to this tag | This is expected. The Formatted Value applies any display transformation configured on the tag (e.g. a boolean mapped to "Running"/"Stopped", or a number with 2 decimal places). The Raw Value is the underlying stored value |
| The Copy button copies nothing or pastes blank content | The browser blocked clipboard access — clipboard write requires a secure context (HTTPS) in modern browsers | Access the Historian via HTTPS rather than HTTP. If HTTPS is not yet configured, you can manually select the grid content and copy it using Ctrl+C as an alternative |