HMI Alarming
PLCnext Engineer enables you to display alarms generated by the controller in your HMI application. Alarms are messages informing about the status changes in the controller. To interact with the alarming system of the controller, the eHMI runtime fills a specific structure variable with the alarm information. The structure variable is part of the HMI data types (available by default in the HMI alarming library). By binding this structure variable to an HMI tag, interacting (for example, alarm acknowledgment and confirmation, sorting and selecting alarms etc.) with the alarming system is possible.
To visualize and control the alarms in the HMI application, PLCnext Engineer provides default HMI alarming symbols which can be found in the 'HMI Alarming' folder under the 'COMPONENTS | HMI' category.
This topic contains the following sections:
AlarmList symbol
The AlarmList symbol provides a predefined alarm table which shows the alarms reported by the alarming system. The table allows the user to interact with the alarming system. Each row in the AlarmList symbol is represented by an own AlarmRow symbol (see the following description).
AlarmList symbol
The alarming table is composed of various elements such as a text list, buttons, text fields, column headers etc. (see the following description). All these elements are used to emulate the appearance of the alarming table.
The connection to the alarming system is done via the AlarmingAccess structure pre-defined in the HmiDataTypes worksheet (see the description below). The AlarmingAccess structure is filled with the alarm information queried from the controller. By binding either an application local tag or page local tag of the type AlarmingAccess to the AlarmList symbol parameter, displaying the alarm information and manipulating the alarm settings is possible.
AlarmList components
The AlarmList symbol is composed of the following elements. All elements are configured as symbol parameters which enables interaction with the alarming system.
| AlarmList component | Description |
|---|---|
| Column headers | Allows to sort the alarm table. Clicking into the column header switches the sort order (ascending, descending). |
| Alarm list | Symbol list with the AlarmRow symbol used as symbol instance (see the description below). |
| 'Acknowledge' button | Button that triggers the acknowledgment of one or several selected (checked) alarms in the alarming system. |
| 'Confirm' button | Button that triggers the confirmation of one or several selected (checked) alarms in the alarming system. |
| Selected alarms | Displays the number of selected (checked) alarms in the alarm list. |
| Total alarms | Displays the number of alarms which currently satisfy the filter criterion. |
| 'Select Visible' button | Selects (checks) all alarms that are currently visible in the alarm list. |
| 'Clear Selection' button | Clears the selection of all checked alarms. |
| Scrolling and paging buttons | Buttons that allow to scroll up and down one page or to the top or bottom in the alarm list. |
AlarmRow symbol
The AlarmRow symbol is used as symbol instance for the symbol list configured with the AlarmList symbol (see above). Each AlarmRow symbol represents an alarm within the alarming system of the controller. For each alarm, the alarm properties described in the following table are available and displayed in the alarm list at runtime. Each property corresponds to a structure field of the Alarm structure variable defined in the HmiDataTypes worksheet.
| Alarm information | Description |
|---|---|
| AlarmId | ID of the alarm instance within the controller. |
| AlarmMessage | Alarm message text. |
| AlarmState | Alarm state, for example, 'ACK' = Acknowledged. |
| AlarmSeverity | Severity of the alarm. |
| AlarmActivationTime | Date and time of the last acknowledgment of the alarm. |
| AlarmConfirmationTime | Date and time of the last confirmation of the alarm. |
HMI Alarming data types
The structure variables used to interact with the alarming system within the controller are declared in the HmiDataTypes worksheet (available in the COMPONENTS area under the 'Programming | HMI Alarming | Data types' folder). With help of the pre-defined structure variables, interacting with the alarming system is possible.
The AlarmingAccess structure variable is the entry point to the alarm visualization and manipulation in the HMI application. This structure provides the alarm information and holds the query filter, paging settings, scrolling settings, sort criterion, and more. To use the AlarmingAccess structure variable for the HMI alarm visualization and manipulation via the AlarmList symbol, a tag (either application local tag or page local tag) of type AlarmingAccess has to be created and bound to the symbol parameter of the AlarmList (see the following description).
Using the AlarmList symbol
To use the AlarmList symbol in your visualization, proceed as follows:
- Create an application local tag or page local tag of type 'AlarmingAccess' as described in the topic "Local HMI Tags".
- Open an existing HMI page or create a new page and drag an instance of the AlarmList symbol from the COMPONENTS area into the page.
- Go to the 'Parameters' tab of the AlarmList symbol and bind the symbol parameter 'p' to the previously created tag of type AlarmingAccess.
