Adapter for OPC 10.3 | webMethods Adapter for OPC Documentation | webMethods Adapter for OPC Installation and User's Documentation | Adapter Listeners and Listener Notification | Data Change Notification | Using Data Change Notification
 
Using Data Change Notification
*To use data change notification
1. In the Adapter Notification Editor, Click the Add Items tab
In the Add Items tab, click for node selection. You can select multiple nodes at a time from Node Selector. The following fields perform the operation:
Field
Description
Search Node
Searches the node.
Select All
Selects all check boxes for the variable nodes.
Clear All
Deselects all check boxes for the variable nodes.
After selecting the nodes from Node Selector, the selected nodes appear in the Add Items tab. The nodes available in the Add Items tab appear as disabled in the Node Selector.
Parameter
Description/Action
Extended Node Id
Displays the extended node id of the selected event source node id. The extended node id is represented in the following format: nsu=<namespace uri>; Id type=Id value
Node Id
The unique id of the selected event source node id to be monitored.
Sampling Interval (ms)
The fastest rate at which the OPC UA server should sample its underlying source for data changes.
Default : 0
Message Queue Size
The maximum number of messages stored in the queue for delivery.
Default : 0
Discard Oldest Message
*True. The oldest message from the queue gets discarded.
*False. No messages are discarded. If the queue size is full, any new messages are ignored.
Monitoring Mode
*Default. The monitoring mode specified during configuration of the listener.
Note:
All the other options override the listener's monitoring mode at each item level.
*Reporting. The datasource is sampled and the notification is sent to the Adapter for OPC.
*Sampling. The datasource is only sampled and no notification is sent to the Adapter for OPC.
*Disabled. The datasource is disabled.
Filter
Defines the conditions on which you want to receive data change notifications.
When the filter settings are set. a drop-down appears with the specified filter names.
2. The filter settings are as follows:
Parameter
Description/Action
Filter Name
The name of the filter.
Trigger Condition
The types of trigger conditions that enable the notification:
*Status / Value. Notifies if either the status or the value changes.
*Status. Notifies if only the status changes.
Note:
Since there is no value in this type of trigger condition, Deadband Type and Deadband Value are not applicable.
*Status / Value / Timestamp. Notifies if either the status, the value or the timestamp changes.
Deadband Type
It defines the type of Deadband Value applied. The following are the types of deadband available:
*Absolute. If the absolute change in the last data value and new data value is greater than the value specified, it triggers the notification.
*Percent. If the changed data value is greater than the percentage of the configured value, it triggers the notification.
*None. No deadband evaluation is done.
Deadband Value
The given value based on the Deadband Type.