Binary Lighting Output

A Binary Lighting Output object controls a light that is either on or off, and it adds lighting features that would otherwise need custom programming. The best known is blink-warn: the lights flash briefly before they switch off, so anyone still in the room has time to react. Several writers share the output through a priority array.

Typical uses

• A relay-switched lighting circuit
• Office lights turned on by a schedule at 7:00
• A warning blink before lights switch off at close
• A corridor circuit that stays on during egress

Key properties

Property	What it holds
Present_Value	The commanded state. Besides on and off, a client can write a blink-warn command: WARN, WARN_OFF or WARN_RELINQUISH, or STOP.
Blink_Warn_Enable	Turns the warning blink on or off for this circuit.
Egress_Time	How long the lights stay on after a WARN_RELINQUISH command before the value is given up.
Feedback_Value	The actual state of the lights, for comparison with the command.
Priority_Array	Sixteen slots that arbitrate between writers. Relinquish_Default is used when all are empty.

How it behaves

Present_Value is commandable. With intrinsic reporting, the standard applies the NONE event algorithm: the object can report fault conditions, but no alarm algorithm runs.

With the CAS BACnet Stack

Enable it with the STACK_OPTION_OBJECT_TYPE_BINARY_LIGHTING_OUTPUT build option. Add each object with BACnetStack_AddObject. The stack always treats it as commandable and reads the priority array through your callbacks instead of calling a plain Present_Value getter. Register your other property callbacks as for any object type.

Related object types

Lighting Output, Binary Output, Channel

Properties

The properties ASHRAE 135-2024 clause 12.55 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	BACnetBinaryLightingPV	W	yes	yes	Built by the stack from the priority array your callbacks serve, or Relinquish_Default when every slot is empty.
Description	CharacterString	O	no	no	""
Status_Flags	BACnetStatusFlags	R	yes	no	Built by the stack from your callbacks.
Event_State	BACnetEventState	O1	no	no	0
Reliability	BACnetReliability	O	no	no	0
Out_Of_Service	Boolean	R	yes	no	false
Blink_Warn_Enable	Boolean	R	yes	no	false
Egress_Time	Unsigned	R	yes	no	0
Egress_Active	Boolean	R	yes	no	false
Feedback_Value	BACnetBinaryLightingPV	O	no	no	No default: the read fails.
Priority_Array	BACnetARRAY[16] of BACnetOptionalBinaryLightingPV	R	yes	no	Built by the stack from your callbacks.
Relinquish_Default	BACnetBinaryLightingPV	R	yes	no	No default: value-not-initialized until a callback or a client write supplies one.
Power	Real	O	no	no	0.0
Polarity	BACnetPolarity	O	no	no	0
Elapsed_Active_Time	Unsigned32	O2	no	no	0
Time_Of_Active_Time_Reset	BACnetDateTime	O2	no	no	No default: the read fails.
Strike_Count	Unsigned	O3	no	no	0
Time_Of_Strike_Count_Reset	BACnetDateTime	O3	no	no	No default: the read fails.
Event_Detection_Enable	Boolean	O1,4	no	no	false
Notification_Class	Unsigned	O1,4	no	no	0
Event_Enable	BACnetEventTransitionBits	O1,4	no	no	An empty bit string.
Acked_Transitions	BACnetEventTransitionBits	O1,4	no	no	An empty bit string.
Notify_Type	BACnetNotifyType	O1,4	no	no	0
Event_Time_Stamps	BACnetARRAY[3] of BACnetTimeStamp	O1,4	no	no	No default: the read fails.
Event_Message_Texts	BACnetARRAY[3] of CharacterString	O4	no	no	""
Event_Message_Texts_Config	BACnetARRAY[3] of CharacterString	O4	no	no	""
Reliability_Evaluation_Inhibit	Boolean	O5	no	no	false
Property_List	BACnetARRAY[N] of BACnetPropertyIdentifier	R	yes	no	Held by the stack.
Current_Command_Priority	BACnetOptionalUnsigned	R	yes	no	Built by the stack from your callbacks.
Value_Source	BACnetValueSource	O6,8,10	no	no	No default: the read fails.
Value_Source_Array	BACnetARRAY[16] of BACnetValueSource	O7,9	no	no	No default: the read fails.
Last_Command_Time	BACnetTimeStamp	O7,9	no	no	No default: the read fails.
Command_Time_Array	BACnetARRAY[16] of BACnetTimeStamp	O9	no	no	No default: the read fails.
Audit_Level	BACnetAuditLevel	O11	not in profile	not in profile	No default: the read fails.
Auditable_Operations	BACnetAuditOperationFlags	O11	not in profile	not in profile	No default: the read fails.
Audit_Priority_Filter	BACnetOptionalPriorityFilter	O11	not in profile	not in profile	No default: the read fails.
Color_Reference	BACnetObjectIdentifier	O12	no	no	No default: the read fails.
Color_Override	Boolean	O13	no	yes	false
Override_Color_Reference	BACnetObjectIdentifier	O13	no	no	No default: the read fails.
Tags	BACnetARRAY[N] of BACnetNameValue	O	no	no	No default: the read fails.
Profile_Location	CharacterString	O	no	no	""
Profile_Name	CharacterString	O	no	no	""