A Networkis the logical representation of wired and wireless technologies and represents the communication means for Devicesthat are connected to it. A Networkinstance is qualified by its Communication Profilecomponents.
Figure 19shows the type hierarchy and the NetworkTypecomponents. It is formally defined in Table 40.
Table 40– NetworkType definition
|
Attribute |
Value |
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|
BrowseName |
NetworkType |
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|
IsAbstract |
False |
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|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Other |
|
Subtype of the 0:BaseObjectType defined in OPC 10000-5. |
|||||
|
0:HasComponent |
Object |
<ProfileIdentifier> |
|
ProtocolType |
MP |
|
ConnectsTo |
Object |
<CPIdentifier> |
|
ConnectionPointType |
OP |
|
0:HasComponent |
Object |
Lock |
|
LockingServicesType |
O |
|
Conformance Units |
|||||
|
DI Network |
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The <ProfileIdentifier> specifies the Protocoland Communication Profilethat this Networkis 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 Protocolas the Network. See also Figure 22for a usage example. They represent the protocol-specific access points for the connected Devices.
In addition, Networksmay also support LockingServices(defined in 7).
Clientsshall use the LockingServicesif they need to make a set of changes (for example, several Writeoperations and Methodinvocations) and where a consistent state is available only after all of these changes have been performed. The main purpose of locking a Networkis avoiding concurrent topology changes.
The lock on a Networkapplies to the Network, all connected TopologyElementsand their components. If any of the connected TopologyElementsprovides access to a sub-ordinate Network(like a gateway), the sub-ordinate Networkand its connected TopologyElementsare locked as well.
If InitLockis requested for a Network, it will be rejected if any of the Devicesconnected to this Networkor any sub-ordinate Networkincluding their connected Devicesis already locked.
If the Online/Offline model is supported (see 6.3), the lock always applies to both the online and the offline version.