====== Adding a Bar Chart to an HMI Schema ======

The Chart gadget in the HMI Editor can display data as a continuous line or, as of IDE version 2.7.18, as a **Bar chart**. This page covers adding a Chart gadget to your schema, switching its Type to Bar, and binding it to data via Chart Mappings.

> **Requires Mervis IDE 2.7.18 or later.** Earlier builds (e.g. 2.7.14) only offer **Line** as a Type option for the Chart gadget — Bar is not available.

===== 1. Opening the HMI Gadget Explorer =====

Open the **View** menu and select **HMI Gadget Explorer**.

{{:en:mervis-ide:35-help:030-hmi_new:bar_chart_1.png?nolink&800}}\\
//The View menu, with HMI Gadget Explorer highlighted//

Inside the explorer, expand **Graphic Gadgets**. The **Chart** gadget is listed alongside the other graphical objects (Alarm, Analog Setter, Digital Indicator, etc.).

{{:en:mervis-ide:35-help:030-hmi_new:bar_chart_3.png?nolink&300}}\\
//The Graphic Gadgets list, with Chart available//

===== 2. Adding the Chart Gadget to Your Schema =====

Drag the **Chart** gadget from the explorer onto your schema canvas. Selecting the gadget opens its **Properties** panel on the right, where the ''Self'' and ''HMI'' sections let you configure the chart's name, type, and data.

===== 3. Setting the Chart Type to Bar =====

In the Properties panel, under the **HMI** section, set **Type** to ''Bar''. Two additional fields appear that are specific to the Bar type:

{{:en:mervis-ide:35-help:030-hmi_new:bar_chart_7.png?nolink&800}}\\
//Properties panel with Type set to Bar, showing Bar Interval and Bar Data Count Type//

| Field | Description |
| Type | Set to ''Bar'' to render the chart as bars instead of a continuous line. |
| Bar Interval | The time interval each bar represents (e.g. ''Hour''). |
| Bar Data Count Type | How the value for each bar is calculated from the samples collected within that interval (e.g. ''Minimum in Interval''). |

The chart's other standard properties (Sample Rate, Duration, Legend) apply the same way regardless of Type, and are not specific to Bar charts.

===== 4. Binding Data via Chart Mappings =====

Click into the **Chart Mappings** field in the Properties panel to open the Chart Mappings dialog. This dialog has two parts: **axis definitions** (top) and **data series** (bottom).

{{:en:mervis-ide:35-help:030-hmi_new:bar_chart_8.png?nolink&800}}\\
//Chart Mappings dialog, with one axis and one series configured//

==== Axis Fields ====

| Field | Description |
| Id | Name identifying this axis. Referenced by each series' **Y Axis** setting below. |
| Min | The minimum value of the axis scale. Set to ''auto'' to scale automatically based on the incoming data. |
| Max | The maximum value of the axis scale. Set to ''auto'' to scale automatically based on the incoming data. |

Use **Add** / **Remove** / **Move Up** / **Move Down** to manage multiple axes, useful when plotting series with very different value ranges on the same chart.

==== Series Fields ====

| Field | Description |
| Name | Display name for this data series, shown in the chart legend. |
| Color | The color used to render this series' bars (or line, for Line-type charts). |
| Thickness | The bar or line thickness, in pixels. |
| Text | Label text shown alongside the series value. |
| Format String | Numeric format applied to displayed values (e.g. ''00.0'' displays one decimal place). |
| Unit | The unit label appended to displayed values (e.g. ''kPA''). |
| Show Points | Toggles whether individual data points are marked on the chart. |
| Variable | The data point this series is bound to. |
| Y Axis | Which of the axes defined above this series' values are plotted against. |

Use **Add** / **Remove** / **Move Up** / **Move Down** to manage multiple series on the same chart.

===== Related Pages =====

  * **[[en:mervis-ide:35-help:030-hmi_new:040-hmi_new_graphic|HMI graphical objects]]** – Overview of all Graphic Gadgets, including Chart.
  * **[[en:mervis-ide:35-help:030-hmi_new:005-hmi_new|Description of HMI Editor]]** – General introduction to the HMI Editor.