The parameters are shared between WriterGroupand ReaderGroup.

The parameters are related to PubSub NetworkMessagesecurity. See 5.4.3for an introduction of PubSub security and 8for the definition of the PubSub Security Key Service.

The SecurityModeindicates the level of security applied to the NetworkMessagespublished by a WriterGroupor received by a ReaderGroup. The MessageSecurityMode DataTypeis defined in OPC 10000-4.

The SecurityGroupIdwith DataType Stringis the identifier for a SecurityGroupin the Security Key Server. It is unique within a SKS.

The parameter is null if the SecurityModeis NONE_1.

If the SecurityModeis not NONE_1 the SecurityGroupIdidentifies the SecurityGroup. The SecurityGroup defines the SecurityPolicy and the security keys used for the NetworkMessagesecurity. The PubSubGroupdefines the SecurityModefor the NetworkMessagessent by the group.

SecurityKeyServicesis an array of the DataType EndpointDescriptionand definesone or more Security Key Servers(SKS) that manage the security keys for the SecurityGroupassigned to the PubSubGroup. The EndpointDescription DataTypeis defined in OPC 10000-4.

The parameter is null if the SecurityMode is NONE_1.

Each element in the array is an Endpointfor an SKS that can supply the security keys for theSecurityGroupId. Multiple Endpointsexist because an SKS may support multiple transport profiles and/or may have multiple redundant instances. The UserTokenPoliciesin each Endpointspecify what user credentials are required. OPC 10000-4describes UserTokenPoliciesin more detail.

The MaxNetworkMessageSizewith DataType UInt32indicates the maximum size in bytes for NetworkMessagescreated by the WriterGroup. It refers to the size of the complete NetworkMessageincluding padding and signature without any additional headers added by the transport protocol mapping. If the size of a NetworkMessageexceeds the MaxNetworkMessageSize,the behaviour depends on the message mapping.

The transport protocol mappings defined in 7.3may define restrictions for the maximum value of this parameter.

Note 1: The value for the MaxNetworkMessageSizeshould be configured in a way that ensures that NetworkMessagestogether with additional headers added by the transport protocol are still smaller or equal than the transport protocol MTU.

The GroupPropertiesparameter is an array of DataType KeyValuePairthat specifies additional properties for the configured group. The KeyValuePair DataTypeis defined in OPC 10000-5and consists of a QualifiedNameand a value of BaseDataType.

The mapping of the name and value to concrete functionality may be defined by transport protocol mappings, future versions of this specification or vendor specific extensions.

This Structure DataTypeis an abstract base type for PubSubGroups. The PubSubGroupDataTypeis formally defined in Table 20.

Table 20– PubSubGroupDataType Structure

Name

Type

Description

PubSubGroupDataType

Structure

name

String

The name of the PubSubGroup.

enabled

Boolean

The enabled state of the PubSubGroup.

securityMode

MessageSecurityMode

Defined in 6.2.4.2.

securityGroupId

String

Defined in 6.2.4.3.

securityKeyServices

EndpointDescription[]

Defined in 6.2.4.4.

maxNetworkMessageSize

UInt32

Defined in 6.2.4.5.

groupProperties

KeyValuePair[]

Defined in 6.2.4.6.

The PubSubGroupDataType Structurerepresentation in the AddressSpaceis defined in Table 21.

Table 21– PubSubGroupDataType Definition

Attributes

Value

BrowseName

PubSubGroupDataType

IsAbstract

True

References

NodeClass

BrowseName

IsAbstract

Description

Subtype of Structure defined in OPC 10000-5.

HasSubtype

DataType

WriterGroupDataType

FALSE

Defined in 6.2.5.6.1.

HasSubtype

DataType

ReaderGroupDataType

FALSE

Defined in 6.2.7.2.1.