SCADA symbol

Who it’s for

Anyone building a SCADA mimic — a process diagram where valves, pumps, tanks and pipes are drawn as the equipment they represent and animate with the plant’s live data. The dashboard is meant to look like the P&ID, and each symbol is a piece of it.

What it does

The SCADA symbol widget renders an SVG symbol whose elements are bound to live data and to actions. An uploaded symbol exposes its own behaviors and properties, so a valve’s body can change color from a state key while its handle triggers an RPC command when clicked.

• The symbol is the widget — an SVG you upload or pick, rather than a generic shape configured to look like equipment.
• Behaviors bind symbol elements to data and actions in three ways: a Value that drives appearance, an Action that sends something to the device, or a Widget action that navigates.
• Properties expose the symbol’s own configurable points, so one uploaded symbol can serve several instances with different settings.
• Because the symbol is SVG, it scales cleanly at any tile size, which matters on a mimic that gets viewed on a wall display and a tablet.
• Symbols can be built once and reused across dashboards, which is what makes a consistent plant diagram maintainable.
• The SCADA symbol widget renders one symbol: a full mimic is many of these positioned together, and the connections between them are drawn with pipe symbols rather than by the widget.

How to set up

Data keys

The SCADA symbol widget takes its data through the behaviors defined in the symbol rather than through a fixed key list.

Attribute	Scope	Operation	Description
Behavior-bound keys	Any for read, Shared / Server for write	Read + Write	A Value behavior reads a key to drive the symbol’s appearance; an Action behavior writes one, or calls RPC, when the element is used.

Method	Direction	Parameters	Sent when
Behavior-bound method	One-way or two-way, as configured	As configured on the behavior	When an Action behavior bound to RPC is triggered on the symbol

Symbol

Setting	Default	Effect
SCADA symbol	Unset	The SVG rendered; upload your own or pick an existing one
Behavior	Empty	Bindings from symbol elements to values, actions and widget actions
Properties	Empty	The symbol’s own configurable settings, exposed per instance

Choose or upload the symbol first — the behaviors and properties available come from the symbol itself, so nothing else can be configured until one is selected.

How to customize

• To animate the symbol from data — add a Value behavior bound to the key that drives it.
• To make the symbol operable — add an Action behavior bound to an RPC call or an attribute write.
• To make the symbol navigate — add a Widget action behavior, which opens a state or dashboard on click.
• To reuse one symbol across instances — expose the differences as Properties and set them per widget.
• To match the mimic’s background — set the card Background and Card padding, usually to match the diagram behind it.

Tips

• Build the symbol’s behaviors around what an operator needs to see, not around everything the device reports. A valve that shows open, closed and faulted is readable across a room; one animating six separate keys is a diagram of the data model rather than of the plant.
• Keep a symbol library and reuse it rather than uploading variants per dashboard. A mimic’s value comes from every valve looking like every other valve, and that consistency is lost the first time somebody uploads a slightly different SVG.