The Device Topology reflects the communication topology of the Devices. It includes Devices and the Networks. The entry point DeviceTopology is the starting point within the AddressSpace and is used to organise the communication Devices for the top level Networks that provide access to all instances that constitute the Device Topology ((sub-)networks, devices and communication elements).

The DeviceTopology node is formally defined in Table 42.

Table 42 – DeviceTopology definition

Attribute	Value
BrowseName	DeviceTopology
References	NodeClass	BrowseName	DataType	TypeDefinition
OrganizedBy by the Objects Folder defined in OPC 10000-5
HasTypeDefinition	ObjectType	BaseObjectType	Defined in OPC 10000-5.
HasProperty	Variable	OnlineAccess	Boolean	PropertyType

OnlineAccess provides a hint of whether the Server is currently able to communicate to Devices in the topology. “False” means that no communication is available.