Methods For Opc Ua Alarms And Conditions - Siemens SIMATIC ET 200AL System Manual

In the columns of the Event area, a selection of event fields is offered, for example, the event
text (Message) and whether the alarm was acknowledged (A=Acknowledged).
Special features of the display of alarms via the OPC UA server of the CPU
The following once again summarizes the special features of the alarm display via OPC UA
Alarms and Conditions for the current status.
Topic
Comment
Pending alarms are not lost after a
server restart
9.3.6.6

Methods for OPC UA Alarms and Conditions

The OPC UA specification Part 9 (OPC 10000-9: Alarms & Conditions) defines methods for
OPC UA servers to enable OPC UA clients to react to state changes, for example.
In the following, the methods are described that are supported by the OPC UA server of the
S7-1500 CPU with their special features.
Requirement
Using the relevant methods for the Alarms and Conditions functionality requires the
following:
• Alarms and Conditions is activated
• For the "Acknowledge" method, the acknowledgment of alarms by OPC UA clients must be
allowed on the server side.
Communication
Function Manual, 05/2021, A5E03735815-AJ
9.3 Using the S7-1500 as an OPC UA server
Explanation
Via OPC UA, you can add a comment to a alarm using the "Add-
Comment" method or the "Acknowledge" method. This comment
is no longer available after a server restart.
The OPC UA server supports the "ConditionRefresh" method with
which it makes the current state of the system available to the
OPC UA client, for example, after download of a new data block
(requires server restart and connection re-establishment).
OPC UA communication
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