Appearance
Trend Chart
Plots one or more tags' historical values over a selectable time range.
In Studio
In Studio, double-click Trend Chart in the Components category of the Components panel. It is added to the open view, where you can drag it into place.
When to use
Use Trend Chart to show how a process value changed over time. For a single current reading, use Value Display, Gauge, or Tank instead.
Properties
| Property | Type | Default | Description |
|---|---|---|---|
| Title | String | Trend | The chart title, shown when Show Title is true. |
| Show Legend | true, false | true | Shows or hides the pen legend. |
| Legend Position | bottom, top | bottom | Where the legend renders relative to the plot: bottom (default) or top. |
| Show Grid | true, false | true | Shows or hides the background grid lines. |
| Refresh (s) | Number | 30 | How often, in seconds, the chart re-queries the historian for new data. The chart clamps this to a minimum of 5 seconds regardless of what is entered. |
| Left Axis Label | String | (none) | Legacy left-axis label. Superseded by the axes configured in the Pens section; kept so a project saved before named axes existed still renders correctly. Leave the Pens section's axes as authored rather than editing this field on a new chart. |
| Left Axis Unit | String | (none) | Legacy left-axis unit — see Left Axis Label. |
| Left Axis Min | String | (none) | Legacy left-axis minimum — see Left Axis Label. Blank means auto-scale. |
| Left Axis Max | String | (none) | Legacy left-axis maximum — see Left Axis Label. Blank means auto-scale. |
| Right Axis Label | String | (none) | Legacy right-axis label — see Left Axis Label. |
| Right Axis Unit | String | (none) | Legacy right-axis unit — see Left Axis Label. |
| Right Axis Min | String | (none) | Legacy right-axis minimum — see Left Axis Label. |
| Right Axis Max | String | (none) | Legacy right-axis maximum — see Left Axis Label. |
| Default Preset | String | (none) | The time-range preset the chart opens on, e.g. 1h. Resolved against the full built-in preset table even if Presets restricts which ones the toolbar offers, so a hidden toolbar can still start on a preset nobody can click to. |
| Presets | String | (none) | Comma-separated list of preset labels to offer in the toolbar, a subset of the built-in 5m/15m/1h/4h/12h/24h/3d/7d table (a custom duration like 30m or 8h is also accepted). Blank offers all of them. |
| Show Toolbar | true, false | true | Shows or hides the preset/range toolbar. |
| Show Title | true, false | true | Shows or hides the title bar. When false, or when Title is blank, no header renders at all. |
| Allow Operator Edits | true, false | true | Lets operators adjust the chart while viewing it: hide or show a pen, move it to another axis, remove it, override an axis range, or change the time window. On by default. The changes last only for that operator's session — they are never saved to the project, and a project reload discards them. Off also fixes the time window, since the toolbar presets are one of those edits. |
Binding
This component has no single value binding.
Trend Chart has no single value binding — each pen (see Pens below) binds its own tag path for its historical data.
Pens
A chart's pens are not schema properties — there is no Properties-panel row for them. They are edited in Studio's own Pens section of the Properties panel, using + Add Pen. Each pen has:
| Field | Description |
|---|---|
| Color | The pen's trace color. |
| Text | The pen's legend label. New pens are named "Pen 1", "Pen 2", … in order added. |
| Tag Path | The historized tag this pen plots. |
| Line Style | The trace line style. |
| Y Axis | Which axis (left, right, or a named axis you have added) this pen's values are scaled against. |
| Stroke Width | The trace line thickness. |
| Show Dots | Marks each historized sample with a dot in addition to the connecting line. |