5 Device communication model ToC Previous Next

5.3 Network ToC Previous Next index

A Network is the logical representation of wired and wireless technologies and represents the communication means for Devices that are connected to it. A Network instance is qualified by its Communication Profile components.

Figure 19 shows the type hierarchy and the NetworkType components. It is formally defined in Table 37.

readme_files/image021.png Figure 19 – NetworkType

Table 37 – NetworkType definition

Attribute Value
BrowseName NetworkType
IsAbstract False

Subtype of the BaseObjectType defined in OPC 10000-5.

References NodeClass BrowseName DataType TypeDefinition ModellingRule
HasComponent Object <ProfileIdentifier>   ProtocolType MandatoryPlaceholder
ConnectsTo Object <CPIdentifier>   ConnectionPointType OptionalPlaceholder
HasComponent Object Lock   LockingServicesType Optional
Conformance Units          
DI Network          

The <ProfileIdentifier> specifies the Protocol and Communication Profile that this Network is used for.

<CPIdentifier> (referenced by a ConnectsTo Reference) references the ConnectionPoint(s) that have been configured for this Network. All ConnectionPoints shall adhere to the same Protocol as the Network. See also Figure 22 for a usage example. They represent the protocol-specific access points for the connected Devices.

In addition, Networks may also support LockingServices (defined in 7).

Clients shall use the LockingServices if they need to make a set of changes (for example, several Write operations and Method invocations) and where a consistent state is available only after all of these changes have been performed. The main purpose of locking a Network is avoiding concurrent topology changes.

The lock on a Network applies to the Network, all connected TopologyElements and their components. If any of the connected TopologyElements provides access to a sub-ordinate Network (like a gateway), the sub-ordinate Network and its connected TopologyElements are locked as well.

If InitLock is requested for a Network, it will be rejected if any of the Devices connected to this Network or any sub-ordinate Network including their connected Devices is already locked.

If the Online/Offline model is supported (see 6.3), the lock always applies to both the online and the offline version.

Previous Next