Alarm Display in Online Mode
Important: Valid license at online change
A login can be executed via online change after a change to the alarm configuration only when a valid CODESYS Online Configuration Change license is available on the PLC. Currently this feature can be used only on devices especially for this purpose.
In online mode, you can influence how the alarms are displayed in the following ways:
Filtering the alarms by the value of latch variables which provide specific information about the alarm
Displaying the alarm events for an explicitly defined period of time
Deleting the alarm history
In the alarm banner: Scrolling through the active alarms
Messages are not saved as a copy in the history.
Effect: If you make a small change to a message (for example, correcting a typing error), then this change has an effect on the history because the corrected message is now displayed there. However, if you completely reconfigure the alarm (change state or condition and update the message), then all previous alarms which were recorded due to the outdated configuration will get the new message in the history. Check on a case-by-case basis whether it is not better to add a new alarm instead of upgrading the outdated alarm.
For more information, see the following: Evaluating Alarm Information in the Program Code