7.3 Designing Effective HMI Screens - 7.3 Designing Effective HMI Screens
Key Concepts
- Clarity and Simplicity
- Consistency
- Visual Hierarchy
- Use of Color
- Alarms and Alerts
- User Feedback
Clarity and Simplicity
Effective HMI screens should be clear and simple, ensuring that operators can quickly understand the information presented. Avoid cluttering the screen with unnecessary details. Use concise labels and icons that are easily recognizable.
Example: Instead of displaying a complex graph with multiple lines, use a simple bar chart that highlights the most critical data points. This allows operators to quickly grasp the essential information without being overwhelmed.
Consistency
Consistency in design helps operators quickly navigate and understand different screens. Use the same color schemes, iconography, and layout across all screens. This reduces the learning curve and minimizes the risk of errors.
Example: If a green button is used to start a process on one screen, it should also be used to start the same process on other screens. This consistency ensures that operators do not have to relearn controls for similar functions.
Visual Hierarchy
Visual hierarchy refers to the arrangement of elements on the screen to guide the operator's attention to the most important information first. Use size, color, and placement to create a clear hierarchy of information.
Example: Highlight critical alarms with a large, red font at the top of the screen. Secondary information, such as process values, can be displayed in smaller, less prominent fonts below.
Use of Color
Color can be a powerful tool in HMI design, but it should be used judiciously. Use color to differentiate between different types of information, such as alarms, warnings, and normal operating conditions. Avoid using too many colors, which can be distracting.
Example: Use red for alarms, yellow for warnings, and green for normal operating conditions. This color coding helps operators quickly identify the severity of any issue.
Alarms and Alerts
Alarms and alerts are crucial for informing operators of critical situations. Ensure that alarms are clearly visible and audible. Provide context for the alarm, such as the source and recommended actions.
Example: When a high-temperature alarm is triggered, display the alarm in a prominent location with a flashing red background. Include details such as the specific sensor that triggered the alarm and suggested actions to resolve the issue.
User Feedback
User feedback is essential for confirming that actions have been executed correctly. Provide visual and auditory feedback when operators interact with the HMI. This helps ensure that commands are received and processed as intended.
Example: When an operator presses a button to start a pump, the button should change color or display a checkmark to indicate that the command was received. An audible beep can also confirm the action.