Escalator

An Escalator object represents one escalator or moving walkway. It reports the direction it runs, its power and mode, whether a passenger alarm is active, and any faults. A building-management client uses it to monitor the equipment. It can belong to an Elevator Group object.

Typical uses

• Show whether a lobby escalator is running up, down or stopped
• Raise an alarm when a passenger presses the emergency stop
• Report fault codes from the escalator controller to a front-end
• List all escalators and moving walkways in a transit station

Key properties

Property	What it holds
Operation_Direction	The direction the escalator is moving, or that it is stopped. Required.
Passenger_Alarm	True while a passenger alarm is active. The standard’s intrinsic alarm watches this property.
Escalator_Mode	The operating mode, such as normal service or out of service. Optional.
Power_Mode	Whether the escalator is powered. Optional.
Fault_Signals	A list of the fault codes currently active. Optional on an escalator.
Elevator_Group	The Elevator Group object this escalator belongs to, or the no-reference value if it belongs to none.

How it behaves

An Escalator is read-only monitoring data, not a commandable object. Where an Escalator reports events itself, the standard pairs it with the CHANGE_OF_STATE algorithm watching Passenger_Alarm for the value TRUE. Reliability can use the FAULT_LISTED fault algorithm. A client sees the usual Event_State and notifications.

With the CAS BACnet Stack

Enable it with the STACK_OPTION_OBJECT_TYPE_ESCALATOR build option. Do not create it with BACnetStack_AddObject. Add the Elevator Group object first with BACnetStack_AddElevatorGroupObject, then call BACnetStack_AddLiftOrEscalatorObject with the Escalator type, its group, the Group_ID and the Installation_ID. The stack stores the group links; you serve everything else through callbacks: the callback you register with BACnetStack_RegisterCallbackGetPropertyCharacterString for Object_Name, the BACnetStack_RegisterCallbackGetPropertyEnumerated callback for Operation_Direction, the BACnetStack_RegisterCallbackGetPropertyBool callback for Passenger_Alarm and Out_Of_Service, and the BACnetStack_RegisterCallbackGetListOfEnumerations callback for Fault_Signals. Enable the optional Power_Mode, Escalator_Mode and Fault_Signals with BACnetStack_SetPropertyEnabled. If you do not serve Operation_Direction or Passenger_Alarm, a read returns an error instead of an invented value. Arm the passenger alarm with BACnetStack_SetAlarmsAndEventsForObjectEnabled and then BACnetStack_SetIntrinsicChangeOfStateAlgorithmBool, with an alarm value of true.

Related object types

Lift, Elevator Group, Notification Class

Properties

The properties ASHRAE 135-2024 clause 12.60 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.
Description	CharacterString	O	no	no	""
Status_Flags	BACnetStatusFlags	R	yes	no	Built by the stack from your callbacks.
Elevator_Group	BACnetObjectIdentifier	R	yes	no	Held by the stack.
Group_ID	Unsigned8	R	yes	no	Held by the stack; a Get callback that answers wins.
Installation_ID	Unsigned8	R	yes	no	Held by the stack; a Get callback that answers wins.
Power_Mode	Boolean	O	no	no (yes while Out_Of_Service is true)	false
Operation_Direction	BACnetEscalatorOperationDirection	R	yes	no (yes while Out_Of_Service is true)	No default: value-not-initialized until a callback or a client write supplies one.
Escalator_Mode	BACnetEscalatorMode	O	no	no (yes while Out_Of_Service is true)	0
Energy_Meter	Real	O	no	no (yes while Out_Of_Service is true)	Held by the stack.
Energy_Meter_Ref	BACnetDeviceObjectReference	O	no	no	Held by the stack once you set it with BACnetStack_SetLiftOrEscalatorEnergyMeterRef.
Reliability	BACnetReliability	O	no	no	0
Out_Of_Service	Boolean	R	yes	no	false
Fault_Signals	BACnetLIST of BACnetEscalatorFault	O	no	no	0
Passenger_Alarm	Boolean	R	yes	no (yes while Out_Of_Service is true)	No default: value-not-initialized until a callback or a client write supplies one.
Time_Delay	Unsigned	O1,2	no	no	0
Time_Delay_Normal	Unsigned	O2	no	no	0
Event_Detection_Enable	Boolean	O1,2	no	no	false
Notification_Class	Unsigned	O1,2	no	no	0
Event_Enable	BACnetEventTransitionBits	O1,2	no	no	An empty bit string.
Event_State	BACnetEventState	O1,2	no	no	0
Acked_Transitions	BACnetEventTransitionBits	O1,2	no	no	An empty bit string.
Notify_Type	BACnetNotifyType	O1,2	no	no	0
Event_Time_Stamps	BACnetARRAY[3] of BACnetTimeStamp	O1,2	no	no	No default: the read fails.
Event_Message_Texts	BACnetARRAY[3] of CharacterString	O2	no	no	""
Event_Message_Texts_Config	BACnetARRAY[3] of CharacterString	O2	no	no	""
Event_Algorithm_Inhibit	Boolean	O2,3	no	no	false
Event_Algorithm_Inhibit_Ref	BACnetObjectPropertyReference	O2	no	no	No default: the read fails.
Reliability_Evaluation_Inhibit	Boolean	O4	no	no	false
Property_List	BACnetARRAY[N] of BACnetPropertyIdentifier	R	yes	no	Held by the stack.
Audit_Level	BACnetAuditLevel	O5	not in profile	not in profile	No default: the read fails.
Auditable_Operations	BACnetAuditOperationFlags	O5	not in profile	not in profile	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	""