Skip to main content

general

Monitor Event operation​

This node is used to monitor a Event or a collection of Event emitted from a OPCUA Object

properties​

  • Name: The name of the node

  • Endpoint: The predefined endpoint of the OPC UA server to connect to.

  • Subscription : The subscription to use for monitoring the nodes, Subscriptions are defined in the "Endpoint" node.

    The frequence at which the server will send a batch of notification is handled by the subscription is specified in this subscription.

    A subscription can typically hold a large number of monitored items.

    This node manages a single or a subset of the monitored items handled by the selected subscription.

  • WhereClause: The where clause to use for filtering the events as a expression (see below)

  • SelectClause: The select clause to use for filtering the events as a expression (see below)

WhereClause​

You can leavt the where clause empty to get all the events or you can use a where clause to filter the events.

example of where clause:​
ofType("AlarmConditionType")

This where clause will only return the events that are of type "AlarmConditionType"

SelectClause​

  • The Select clause allows you to select the fields that you want to get from the event.
  • it contains a list of comma separated fields that you want to get from the event.
  • The fields are selected from the OPCUA Events hierachical tree.
  • The best approach is to open the popup and use the graphical interface to select the fields you want to get from the OPCUA Events hierachical tree.