Use alarm groups for organizing individual alarms in the alarm management of an application. Assign each alarm to only one alarm group. To configure an alarm group, insert an Alarm Group object below an Alarm Configuration object in the Tools tree. The alarm group editor allows you to define settings for an entire group of alarms (such as the archiving type, a shared deactivation variable, and a shared text list). You can create a hierarchical structure of alarm groups in the Tools tree by using folder elements.
The alarm group editor provides a table listing the alarms of the group and the properties of each alarm. You can edit the values in the list. An export and import function to and from a CSV file is also available.
For further information, refer to Configuration of the Alarm Management.
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Element |
Description |
|---|---|
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Text list |
Name of the text list where the alarm message text is saved (also refer to the parameter Message in the next paragraph). It is created automatically when an alarm group is added. The text list can be used for the localization of the messages. You can also select another text list from the list. |
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Archiving |
If you select an alarm storage object from this list, alarm storage is automatically activated. |
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Deactivation |
Enter or select a Boolean variable that deactivates all alarms in this group. When this variable is applied, the alarms will no longer be triggered even if the alarm condition is fulfilled. Alarms that are already active are not affected. |
Enter the properties of the individual alarms in the table columns. Depending on the selected Observation Type, additional parameters are provided in the input fields below the table.
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Column |
Description |
|---|---|
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ID |
This unique ID corresponds to the ID in the associated text list. You can change the ID in the ID field of the table. The ID must always be unique within the alarm group. A change of the ID in the alarm table directly changes the ID in the text list and vice versa. |
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Observation Type |
Select an observation type from the list. Depending on the type, different editing fields are available below the table that define the condition for the alarm. The fields define an expression that triggers the alarm. Refer to the table describing the observation types. |
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Details |
Displays the configuration settings for the selected alarm type. Define the settings in the section below the table for the selected Observation Type: Digital, Upper limit, Lower limit, Outside range, Inside the range, Change or Event or edit the action directly in this Details field. If you enter an expression that does not match the selected Observation Type, the expression is automatically adapted. |
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Deactivation |
Enter an optional Boolean variable for deactivating the alarm. |
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Class |
Select an alarm class from the list. |
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Message |
Enter text for the alarm message that is displayed in an Alarm Table visualization element when the alarm occurs. This text is automatically transferred to the text list associated with the alarm group. You can insert line breaks by pressing Ctrl+Enter. For a list of supported placeholders that are replaced by the present value at runtime, refer to the separate table in this chapter.
NOTE: By default, only one column is available for message text. You can add more columns from the contextual menu which is available in the Type of data property for Column configuration of the Alarm table and Alarm banner visualization elements.
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Min. Pend. Time |
Enter the minimum time the alarm condition must apply before the alarm is triggered. This allows you to inhibit alarms for conditions that occur only for a short time.
Use an IEC 61131-compliant format, for example, |
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Latch Var 1 Latch Var 2 |
The latch variables are used to record additional values when the alarm becomes active. A latch variable must be a scalar type (8-byte) or a STRING or WSTRING type. A latch variable or a latch expression is recorded when the alarm becomes active. This allows you to provide additional information about the alarm.
NOTE: The Alarm table or Alarm banner elements allow you to filter the alarms in the visualization by the contents of the latch variable. See how to include latch variables in the alarm Message in the list of supported placeholders.
Example: When monitoring a motor speed, the temperature and the current are additionally recorded. By default, columns are available for two latch variables. You can add more columns from the contextual menu which is available in the Data type property for column configuration of the Alarm table and Alarm banner visualization elements if configured via the dialog box. |
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Higher Prio. Alarm |
When the alarm is triggered, it can be acknowledged by triggering another alarm. Example: When monitoring a temperature, an alarm of class Warning should be triggered at a temperature > 60 °C and an alarm of type Error at a temperature > 90 °C. If the temperature rises, the alarm of class Warning is displayed starting at 60 °C. At 90 °C and higher, the alarm of type Error is triggered which automatically acknowledges the 60 °C alarm. |
The Details section changes to Digital, Upper limit, Lower limit, Outside range, Inside the range, Change or Event depending on the Observation Type selected.
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Observation Type |
Elements |
|---|---|
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Digital |
Enter the Expression to be monitored on the left-hand side and the expression for the comparison on the right-hand side. In the middle, select the comparison operator = or <>. |
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Upper limit(1) |
Enter the (left and right) Expression as described for the Digital type and select the comparison operator > or >=. Optionally, enter a Hysteresis in %. |
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Lower limit(1) |
Enter the (left and right) Expression as described for the Digital type and select the comparison operator < or <=. Optionally, enter a Hysteresis in %. |
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Outside range(1) |
Enter the Expression to be monitored. Area: The alarm is triggered when the monitored expression is outside the range defined here. The left field defines an expression for the lower limit of this range. The right field defines an expression for the upper limit. The expression to be monitored is displayed in the field in the middle. Set the comparison operators < or <=accordingly. Optionally, enter a Hysteresis in %. |
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Inside the range(1) |
Enter the Expression to be monitored. Area: The alarm is triggered when the monitored expression is within the range defined here. The left field defines an expression for the lower limit of this range. The right field defines an expression for the upper limit. The expression to be monitored is displayed in the field in the middle. Set the comparison operators < or <=accordingly. Optionally, enter a Hysteresis in %. |
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Change |
Enter the Expression to be monitored. An alarm is triggered when the value changes. |
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Event |
The Event alarm is triggered via a function block call from the library AlarmManager.library. For further information, refer to Calling Event Alarms in the Program. |
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(1) For these Observation Types, you can monitor the specified expression as absolute or relative. Absolute means that the limit value is defined by a fixed value or a variable that returns a fixed value. Relative means that the limit value depends on an expression.
Example: Upper limit: Hysteresis in %: When you specify a hysteresis, the alarm condition is fulfilled until a certain deviation from the specified limit value is reached. The size of the deviation is specified as a percentage [%] of the limit value.
Example: Upper limit: |
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The following placeholders are supported for alarm messages and will be replaced by the present value at runtime.
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Placeholder |
Description |
|---|---|
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Date of the change to the present status. |
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Time of the last status change. |
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Expression (defined within the alarm) that triggered the alarm. |
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Priority of the alarm (defined in the alarm class). |
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Value that caused the alarm condition to become true. |
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Alarm ID as displayed in the first column of an alarm table. |
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Name of the alarm class (defined in the alarm). |
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The complete information about the alarm is displayed. |
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Present value of the monitored variable. |
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Value of the first latch variable at the time when the alarm was triggered. |
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Value of the second latch variable at the time when the alarm was triggered. |
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TRUE in the case of the alarm status Active. FALSE with every other alarm status. |
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Alarm status: 0 = Normal, 1 = Active, 2 = WaitingForConfirmation, 3 = ActiveAcknowledged (still active and already acknowledged) |
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(1) For |
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You can make the following commands for adding and removing additional columns for messages and latch variables available in the contextual menu via the command:
Add message column
Remove message column
Add latch var column
Remove latch var column
You can make the following commands for exporting and importing alarms to and from a CSV file available in the contextual menu via the command:
Export Alarms
The command opens the default dialog box for saving a file in the file system. Select the default file type Alarm Group Export File (*.csv) and click OK to export the present alarm list to a CSV file.
Import Alarms
The command opens the default dialog box for searching for a file in the file system. Select a file of type Alarm Group Export File (*.csv) that describes alarm definitions and click OK to import the alarms.