According to the BACnet protocol documentation:

Specifies the instance of the Network Port object that this Network Port object uses as its lower protocol layer (i.e. transport, routing, datalink, etc). This property allows the Network Port objects in the device to describe the hierarchy of protocols and physical ports in order to support complex network configuration required by some advanced BACnet products. If this property is absent and the Protocol_Level is BACNET_APPLICATION, then it represents all protocol layers in a single object. If this property has a value of 4194303, then this object has not been assigned a lower protocol layer. If the object is capable of representing all protocol layers in a single object, then this is a valid configuration and the object shall behave as if this property were absent. If the object is not capable of representing all protocol layers in a single object, then this is an indication that the object is not yet configured. A Network Port object is misconfigured if the referenced Network Port object has a Protocol_Level of BACNET_APPLICATION, or the referenced Network Port object does not exist.

Property referencePort of object networkPort can be read and written using a single IOTag.

Text Parameters

Numeric Parameters

Tag Value

A 32-bit unsigned integer.