Color

A Color object controls the colour of a light as a pair of coordinates on the CIE chromaticity chart. A lighting device uses it so a client can pick a colour or fade between two colours.

Typical uses

• Set an RGB-style accent light to a colour
• Fade a wall washer from blue to green
• Run a colour scene in a lobby
• Match a light to a brand colour

Key properties

Property	What it holds
Present_Value	The target colour as x and y coordinates, each from 0 to 1.
Color_Command	Starts a fade or other colour operation, such as stopping a fade in progress.
Tracking_Value	The colour the output shows right now while it fades.
In_Progress	Shows whether a fade is under way.
Default_Color	The colour used when the object has no other instruction.
Default_Fade_Time	How long a fade takes when the command does not say.

How it behaves

The standard defines no intrinsic event algorithm for this type. A lighting output points to a Color object to say which one controls its colour. A client sees the colour move gradually while In_Progress is set.

With the CAS BACnet Stack

Enable it with the STACK_OPTION_OBJECT_TYPE_COLOR build option and add each object with BACnetStack_AddObject. The customer callbacks cannot serve this type’s colour properties: there is no callback for an x,y colour value or for a colour command, so Present_Value, Tracking_Value, Default_Color and Color_Command cannot be served in this release. Properties with ordinary datatypes, such as Object_Name through the callback you register with BACnetStack_RegisterCallbackGetPropertyCharacterString, are served as for any object type. If your product needs Color objects, contact Chipkin.

Related object types

Color Temperature, Lighting Output, Binary Lighting Output, Channel

Properties

The properties ASHRAE 135-2024 clause 12.65 defines for this object type.

How to read the table:

• Conformance is what the standard asks of every object of this type: R is required, W is required and writable by a client, O is optional. A digit after the letter marks a condition in the standard that decides when the property is present or writable, such as support for intrinsic reporting.
• Present by default: yes means the stack presents the property as soon as you add the object; no means it is optional and you turn it on with BACnetStack_SetPropertyEnabled. This is the stack’s starting setup, so it can differ from the conformance code.
• Writable is whether a client can write the property by default. Change it with BACnetStack_SetPropertyWritable.
• not in profile means the stack does not offer this property for this object type.
• Value when your callback does not answer: “Held by the stack” means the stack stores and serves the value itself and does not ask your callbacks. Otherwise it is the value the stack answers when your callback declines or is not registered.

Property	Datatype	Conformance	Present by default	Writable	Value when your callback does not answer
Object_Identifier	BACnetObjectIdentifier	R	yes	no	Held by the stack.
Object_Name	CharacterString	R	yes	no	"Object <type>,<instance>", such as "Object 0,1" for Analog Input 1.
Object_Type	BACnetObjectType	R	yes	no	Held by the stack.
Present_Value	BACnetxyColor	W	yes	yes	No default: value-not-initialized.
Tracking_Value	BACnetxyColor	R	yes	no	No default: the read fails.
Color_Command	BACnetColorCommand	W	yes	yes	No default: the read fails.
In_Progress	BACnetColorOperationInProgress	R	yes	no	0
Default_Color	BACnetxyColor	R	yes	no	No default: the read fails.
Description	CharacterString	O	no	no	""
Default_Fade_Time	Unsigned	R	yes	no	0
Transition	BACnetColorTransition	O	no	no	0
Value_Source	BACnetValueSource	O1,2,3	no	no	No default: the read fails.
Audit_Level	BACnetAuditLevel	O4	not in profile	not in profile	No default: the read fails.
Auditable_Operations	BACnetAuditOperationFlags	O4	not in profile	not in profile	No default: the read fails.
Tags	BACnetARRAY[N] of BACnetNameValue	O	no	no	No default: the read fails.
Property_List	BACnetARRAY[N] of BACnetPropertyIdentifier	R	yes	no	Held by the stack.
Profile_Location	CharacterString	O	no	no	""
Profile_Name	CharacterString	O	no	no	""