Alerting (also occasionally referred to as 'alarming'), is a core feature of the Ignition platform. Alerts are conditions that are evaluated with respect to a specific numeric datapoint. Most commonly, alerts are configured on a SQLTag or a Transaction Group item.
Any given datapoint can have multiple conditions that might cause it to be considered "in alert". For example, you might configure an analog tag to be in alert if its value exceeds 50.0, or you might configure a discrete tag to be in alert if its value non-zero. Analog values can have multiple alert states configured for them. Each alert state defines a numeric range where it is considered active, and has a name and a severity.
An alert state becomes active when the value of the datapoint falls within the range of the state. The alert state is said to clear when the datapoint moves outside of the range by at least the alert deadband, if the deadband is configured. When an alert state becomes active or clear, a message is generated and will be consumed by any configured alert storage profiles and alert notification profiles.
The job of an alert storage profile is to store the record of when an alert state for a datapoint became active, when it cleared, and whether or not it has been acknowledged. Typically, this is done by recording the event as a row in an external database.
An alert notification profile takes the messages from the alerting system and uses them to notify people of the event. This is typically done via sending an email. There are several types of alert notification profiles that provide different mechanisms for controlling how notifications are sent to various sets of users.
Information about configuring alerts conditions can be found in Alert Properties under SQLTag configuration.
Both notification and storage profiles offer the ability to filter alert messages on a few basic parameters. Multiple profiles of each type can be created and configured differently in order to filter out different sets of alerts, if desired. The three text based filters, System, Path and State Name, can include wildcard parameters * (any characters) and ? (any single character).