According to the BACnet protocol documentation:

Specifies how a change in the Present_Value transitions from the current level to the target level. A transition comes into effect when the Present_Value is directly commanded or when the current highest priority value has been relinquished. Writing the Lighting commands FADE_TO, RAMP_TO, STEP_ON, STEP_OFF, STEP_UP, or STEP_DOWN shall ignore the Transition property. The transition may be one of NONE, FADE, or RAMP. The transition NONE causes the Present_Value to immediately be set to the target level when the highest priority value has been relinquished. If this property does not exist, then the transition type shall be assumed to be NONE. FADE or RAMP transitions allow a smooth transition of the lighting level when the Present_Value changes. A FADE transition executes a fade operation from the Tracking_Value to the target level using the fade time specified in Default_Fade_Time. A RAMP transition executes a ramp operation from the Tracking_Value to the target level using the ramp rate specified in Default_Ramp_Rate. When a transition results in an operation that may cause the Tracking_Value to differ from the Present_Value, then the In_Progress property shall be set to the value that reflects the operation in progress.

Property transition of object lightingOutput can be read and written using a single IOTag.

Text Parameters

Numeric Parameters

Tag Value

An integer representing one of the options of enumeration <BACnetLightingTransition>.