OpcUaServer alarm acknowledgment processing
An OPC UA client can subscribe and receive OPC UA events from an OPC UA server. The OPC UA client Alarm Manager may allow you to acknowledge a received event back to the OPC UA server. It may also allow the user to command the OPC UA server to enable or disable the source of the received event.
The OPC UA server's OpcUaServerAlarmDeviceExt processes the Acknowledge, Enable, and Disable commands. OpcUaServerAlarmDeviceExt is a child of each namespace component. Each OPC UA server namespace has a frozen slot named AlarmExt. This extension is a type of OpcUaServerAlarmDeviceExt. It keeps track of all of the alarmable points under this namespace. When the extension receives an Acknowledge command for the OPC UA client, it attempts to locate the alarm record being acknowledged and acknowledges the alarm. When the extension receives a Disable command, it disables the alarm from generating any more OPC UA events from the associated control point until it receives an Enable command.