BACnet Points Displayed as Overridden (Purple) on I/A Series R2 Graphics

[Product_Support]

Issue

BACnet controller objects that have not been overridden appear in purple on I/A Series R2 graphic screens, indicating an override condition incorrectly.

Product Line

TAC IA Series

Environment

• I/A Series R2 graphic screens
• BACnet controller inputs displayed on Niagara graphics
• MNB controller firmware version 1.2 or higher

Cause

• Purple color indicates the BACnet OVERRIDDEN flag is set to TRUE.
• This behavior is normal and results from compliance with BACnet Specification 135-2004 for BTL certification.
• Read-only BACnet objects (e.g., Analog Value, Binary Value) must indicate an override condition because their Present Value cannot be changed via BACnet services.
• Niagara interprets this as overridden, even though it is simply read-only.

Resolution

Two approaches to prevent purple override indication:

1. Buffer the Value Using Native Niagara Objects

   • Use a Niagara AI object to display the value without transferring the override condition.
   • If BACnet points are in a poll-on-demand container, add a gx type object linked to the BACnet point (invisible) to initiate polling.
   • Display the value using another gx object linked to the AI object.

2. Disable Status Color on GxText Objects

   • Configure the statusColorEnabled property of the GxText object to false.
   • This prevents the purple background from appearing.