5 Service Sets ToC Previous Next

5.13 Subscription Service Set ToC Previous Next

5.13.3 ModifySubscription ToC Previous Next

5.13.3.1 Description ToC

This Service is used to modify a Subscription.

Illegal request values for parameters that can be revised do not generate errors. Instead the Server will choose default values and indicate them in the corresponding revised parameter.

Changes to the Subscription settings shall be applied immediately by the Server. They take effect as soon as practical but not later than twice the new revisedPublishingInterval.

5.13.3.2 Parameters ToC

Table 90 defines the parameters for the Service.

Table 90 – ModifySubscription Service Parameters

Name Type Description
Request    
   requestHeader RequestHeader Common request parameters (see 7.28 for RequestHeader definition).
   subscriptionId IntegerId The Server-assigned identifier for the Subscription (see 7.14 for IntegerId definition).
   requestedPublishingInterval Duration This interval defines the cyclic rate that the Subscription is being requested to return Notifications to the Client. This interval is expressed in milliseconds. This interval is represented by the publishing timer in the Subscription state table (see 5.13.1.2).
The negotiated value for this parameter returned in the response is used as the default sampling interval for MonitoredItems assigned to this Subscription.
If the requested value is 0 or negative, the Server shall revise with the fastest supported publishing interval.
   requestedLifetimeCount Counter Requested lifetime count (see 7.5 for Counter definition). The lifetime count shall be a minimum of three times the keep keep-alive count.
When the publishing timer has expired this number of times without a Publish request being available to send a NotificationMessage, then the Subscription shall be deleted by the Server.
   requestedMaxKeepAliveCount Counter Requested maximum keep-alive count (see 7.5 for Counter definition). When the publishing timer has expired this number of times without requiring any NotificationMessage to be sent, the Subscription sends a keep-alive Message to the Client.
The negotiated value for this parameter is returned in the response.
If the requested value is 0, the Server shall revise with the smallest supported keep-alive count.
   maxNotificationsPerPublish Counter The maximum number of notifications that the Client wishes to receive in a single Publish response. A value of zero indicates that there is no limit.
   priority Byte Indicates the relative priority of the Subscription. When more than one Subscription needs to send Notifications, the Server should de-queue a Publish request to the Subscription with the highest priority number. For Subscriptions with equal priority the Server should de-queue Publish requests in a round-robin fashion.
A Client that does not require special priority settings should set this value to zero.
       
Response    
   responseHeader ResponseHeader Common response parameters (see 7.29 for ResponseHeader definition).
   revisedPublishingInterval Duration The actual publishing interval that the Server will use, expressed in milliseconds. The Server should attempt to honour the Client request for this parameter, but may negotiate this value up or down to meet its own constraints.
   revisedLifetimeCount Counter The lifetime of the Subscription shall be a minimum of three times the keep-alive interval negotiated by the Server.
   revisedMaxKeepAliveCount Counter The actual maximum keep-alive count (see 7.5 for Counter definition). The Server should attempt to honour the Client request for this parameter, but may negotiate this value up or down to meet its own constraints.

5.13.3.3 Service results ToC

Table 91 defines the Service results specific to this Service. Common StatusCodes are defined in Table 177.

Table 91 – ModifySubscription Service Result Codes

Symbolic Id Description
Bad_SubscriptionIdInvalid See Table 177 for the description of this result code.

Previous Next