Use either the display's built-in out-of-range blinking behavior or place a full-screen indicator behind the other graphics and control that indicator with a Boolean state from the controller.
Choose the Required Alarm Behavior
| Required behavior | Supported method | Constraint |
|---|---|---|
| Blink when the value exceeds the configured limit | Enable checking on the signal display's Range tab | The evidence confirms blinking, not a direct color change. |
| Change the apparent screen background | Place a full-screen indicator behind all other graphic objects | This is a layered-screen workaround rather than a signal-display color property. |
Configure Out-of-Range Blinking
Open the signal display's Range tab and enable Check. When the displayed value exceeds the configured range, the indicator blinks. Use this method when blinking provides an adequate setpoint alarm and a background-color transition is unnecessary.
Implement a Background Color State
- Create an indicator that covers the full screen.
- Place it behind the remaining graphic elements so it acts as the screen background.
- Generate the alarm state in the controller by comparing the process value with the setpoint.
- Test values below and above the setpoint, confirming that the background state follows the controller output while foreground objects remain visible.
Perform the comparison in the controller where possible. The evidence does not define available colors, object properties, communication addresses, or the comparison behavior at exact equality; confirm those items in the project configuration before commissioning.
FAQ
No direct text or background color change is identified for the signal display. Use a full-screen indicator behind the graphics to create an apparent background change.
Open the signal display's Range tab and enable Check. The indicator then blinks when the value exceeds the configured range.
This reduces unnecessary HMI calculations and gives the indicator a direct state input.