What is HMI Scripting: Definition and Examples

HMI scripting is writing small programs or scripts inside a Human-Machine Interface (HMI) system to automate tasks, control devices, or customize user interactions. It allows operators to interact dynamically with machines by running code triggered by events or user actions.

How It Works

Think of HMI scripting like programming a remote control for a machine. Instead of pressing buttons manually every time, you write simple instructions that the HMI follows automatically. These scripts can respond to events like button clicks, alarms, or changes in sensor data.

Inside the HMI software, scripting languages (often similar to JavaScript or VBScript) let you create logic to update displays, send commands to the PLC, or log data. This makes the interface smarter and more interactive, helping operators manage complex processes easily.

Example

This example shows a simple HMI script that changes the color of a button when clicked to indicate a machine start.

javascript

function onStartButtonClick() {
    // Change button color to green
    this.setProperty("StartButton", "backgroundColor", "#00FF00");
    // Send start command to PLC
    plc.writeTag("MachineStart", true);
}

// Attach the function to the button click event
this.getObject("StartButton").onClick = onStartButtonClick;

Output

When the StartButton is clicked, its color changes to green and the PLC tag 'MachineStart' is set to true.

When to Use

Use HMI scripting when you want to add custom behavior beyond standard button presses or displays. For example, you can automate alarm handling, create dynamic menus, or validate user input before sending commands.

It is especially useful in manufacturing plants, building automation, or any system where operators need clear feedback and control over machines. Scripting helps reduce errors and speeds up operator actions by automating repetitive tasks.

Key Points

• HMI scripting automates and customizes machine interfaces.
• It uses simple code triggered by user actions or system events.
• Scripting improves operator experience and process control.
• Common languages include JavaScript-like syntax.
• It connects the HMI with PLC commands and data.

Key Takeaways

HMI scripting lets you automate tasks and customize machine interfaces with code.

Scripts run inside the HMI software, reacting to user actions or system events.

It improves control and feedback for operators in industrial automation.

Common uses include changing displays, sending commands, and handling alarms.

Knowing basic scripting helps make HMIs smarter and more user-friendly.