According to the BACnet protocol documentation:

Defines a standardized object whose properties represent the externally visible characteristics of a binary output. A "binary output" is a physical device or hardware output that can be in only one of two distinct states. In this description, those states are referred to as ACTIVE and INACTIVE. A typical use of a binary output is to switch a particular piece of mechanical equipment, such as a fan or pump, on or off. The state ACTIVE corresponds to the situation when the equipment is on or running, and INACTIVE corresponds to the situation when the equipment is off or idle.

Objects of type binaryOutput have the following properties:

•ackedTransitions

•activeText

•changeOfStateCount

•changeOfStateTime

•commandTimeArray

•currentCommandPriority

•description

•deviceType

•elapsedActiveTime

•eventAlgorithmInhibit

•eventAlgorithmInhibitRef

•eventDetectionEnable

•eventEnable

•eventMessageTexts

•eventMessageTextsConfig

•eventState

•eventTimeStamps

•feedbackValue

•inactiveText

•interfaceValue

•lastCommandTime

•minimumOffTime

•minimumOnTime

•notificationClass

•notifyType

•objectIdentifier

•objectName

•objectType

•outOfService

•polarity

•presentValue

•priorityArray

•profileLocation

•profileName

•propertyList

•reliability

•reliabilityEvaluationInhibit

•relinquishDefault

•statusFlags

•tags

•timeDelay

•timeDelayNormal

•timeOfActiveTimeReset

•timeOfStateCountReset

•valueSource

•valueSourceArray