Shelving an alarm tells the alarm system that it should ignore the alarm, preventing new alarm events from being created. Shelving always has a duration associated it. At the end of the shelving period, the alarm will evaluate it's source tag, potentially creating a new alarm event. Shelving is useful to temporarily disable an alarm for a period of time, such as maintenance periods.
Shelved alarms will not generate alarm notifications. In addition, shelving an alarm will hide all alarm event for that alarm from the Vision and Perspective Alarm Status Table components.
Alarms in Transaction Groups
OPC items in Transaction groups can also have alarms configured on them, similar to tags. This functionality exists mostly for legacy reasons, and offers no real benefit over configuring alarms on a Tag instead.
Alarm configuration in Ignition is flexible and highly customizable to your needs. You can configure alarms with one alarm on a Tag or multiple alarms on a Tag. You can add alarms in UDTs so every instance of that Tag will automatically have alarms configured when a new instance of your Tag is created. You can use the alarm settings to create alarms that equal or don't equal a setpoint, above or below a setpoint, between setpoints, outside setpoints, dynamic setpoints, out of range, bad quality, etc. Alarms can be configured for any alarm condition imaginable.
The image below shows an alarm configured on an OPC Tag. You can see that an alarm has quite a few properties including alarm mode settings where you can set specific alarm attibute values.
Monitoring Alarm Status
Alarms can be monitored from Vision and Perspective using their respective Alarm Status Table components. In addition, the system.alarm.queryStatus function can be used to retrieve realtime alarm status. You can Acknowledge or Shelve, and you can filter on Alarm Status properties, show or hide alarm property information, reorganize columns, or view alarm details, notes, and history of an alarm.
Alarm Count Tags
Ignition provides a set of System Tags to view information about the Ignition server which includes four Tags that count the number of alarms in each state. A quick way to see if any alarms are currently active and get an alarm count is to add a Label component on the Navigation window. The four system alarm states are:
- Active and Unacknowledged
- Active and Acknowledged
- Clear and Acknowledged
- Clear and Unacknowledged
In the Tag Browser of the Designer, scroll down to the System > Gateway > Alarming folder. These system Tags can easily be used to visualize all alarms in the system.
How to View Alarm History
The Alarm Journal stores historical information about alarms in a database. It stores basic data about alarms that have occurred, such as their source and timestamp, associated data on an alarm, and the values of an alarm's properties at the time the event occurred. It captures all status changes for each alarm, as well as acknowledgement to an external SQL database of your choosing. To begin viewing alarm history, all you need to do is create an Alarm Journal Profile in the Gateway webpage.
Like the Alarm Status Table, the Alarm Journal enables you to filter on alarm history properties. The alarms are color coded so you know what each status represents. The Date Range is a very common filter type since users typically want to filter for alarm events within a specific period of time.
Alarms can also generate notifications that are delivered to users allowing Ignition to immediately communicate events and problems to your users. Alarm Notification Pipelines control how and when notifications are sent to users. You can select the delivery channel for how alarms are sent: Email, SMS, or Voice. The notification system has access to Ignition's Authentication Profiles so users can easily be added to notification On-Call Rosters. Schedules can be created allowing users to receive notifications only when on-schedule, so there is no need to worry about notifying a supervisor or manager when they are not on-site, or if it's in the middle of the night. Pipelines coupled with on-call rosters and schedules allow you to build your own custom alarm notification process.
The On-Call Roster is a collection of users that are notified when an alarm occurs. When an alarm is triggered, a notification is sent to a designated On-Call Roster where it evaluates the users schedules, and only notifies those users that have an active schedule.
Roster Management from the Vision Client Window
Alarm Notification Pipelines
The Alarm Notification Pipeline feature is an innovative tool that lets you easily create routes for your alarms. By designing your own alarm notification routing, you have control of what happens when an alarm goes active, when an alarm is sent out, and who receives the alarm notification.
The alarm notification pipeline has a simple drag-and-drop interface so you can build various types of alarm logic. Its built-in pipeline block functionality lets you delay sending alarm notifications, escalate higher priority alarms to a different group of users, consolidate multiple alarms so recipients aren’t flooded with messages, and distribute specific alarm types to different contact groups.
Alarm notification pipelines can be very simple to very complex. In this simple notification pipeline, when an alarm is triggered, the people listed in the On-call Roster are notified via Email. If no one acknowledges the alarm in 20 seconds, the alarm notification is routed back to the same users listed in the On-Call Roster.
In this more complex alarm notification pipeline, if an operator doesn't respond to the alarm after three attempts, the pipeline jumps it to another pipeline (possibly an escalation pipeline).
To learn more about building your own pipelines, go to Alarm Notification Pipelines.