Siemens SIMATIC ET 200AL System Manual page 1408

Display of alarms in the TIA Portal
During runtime, you have the option of viewing the alarms in the TIA Portal: The alarm
display is located directly under the alarm editor ("Diagnostics" tab > "Alarm display" tab).
The following applies to the state and acknowledgment behavior:
• When you click on the "Current alarms" button, alarms that have been recently incoming,
outgoing or acknowledged are displayed. Only alarms with a state and alarms requiring
acknowledgment are displayed here. You can also acknowledge an alarm requiring
acknowledgment (blue font) in this view via the shortcut menu or using the
"Acknowledge" button.
• If you want to observe the chronological development (e.g. alarm came in, was
acknowledged and went out), you need to click the "Alarm archive" button. The three
events that belong to this alarm are listed one after another only in this view. You can
only find the current state in the "Current alarms" view.
• Info reports (alarms with the "Information only" property) are only displayed in the "Alarm
archive" view. Because these alarms are only triggered once and not buffered, they do not
appear in the "Current alarms" view.
• PLC supervisions are also shown in the alarm display.
• System alarms usually belong to the "No Acknowledgement" alarm class with the
"Information only" option. These alarms are logged in the diagnostics buffer in the CPU
and thus allow the sequence of system alarms to be analyzed over a limited period. In
contrast, operating state changes that are also logged in the diagnostics buffer have a
state, which means it is indicated that or when a CPU went into STOP state and if or when
it exited this state again, for example, entered RUN state. This information is displayed
with the states "incoming/outgoing".
Communication
Function Manual, 05/2021, A5E03735815-AJ
OPC UA communication
9.3 Using the S7-1500 as an OPC UA server
287