Alarm Types Overview

An alarm type describes the behavior and evaluation logic behind an alarm. Defining Hyper Alarm Server™ alarm types is essential to the alarm configuration. Typically, you define alarm types for your configuration before you can associate them with one or more alarm areas—considered the sources (tags).

You can access predefined alarm types from the Project Explorer pane in Workbench, under Alarms and Notifications and Hyper Alarm Server nodes. Predefined alarms are considered standard alarms types and can be used for alarm customization. View predefined alarm type descriptions.

Alarm Type	Description
Alarm Limit - compat	Alarm Limit - compat (compatible) mimics the legacy AlarmWorX limit alarm.
Digital	Triggers an alarm if the input state matches the alarm state setting of True or False, On / OFF type of alarm signal. For example, a pump trip alarm or monitoring exit doors in a building.
Digital - compat	Digital - compat (compatible) the same as Digital—the alarm is either normal or in an alarm state. This alarm type mimics the legacy AlarmWorX digital alarm.
Limit	Triggers an alarm if the input value exceeds the specified high or low limits. For example, monitor tank levels, temperature setting against low and high limits.
Hi Limit	Triggers an alarm if the input value exceeds the specified high (Hi and HiHi) limit setpoint.
Lo Limit	Triggers an alarm if the input value is equal to or falls below the specified low (Lo and LoLo) limit setpoint.
Rate of Change from Historical Data	Simulates rate of change alarm based on historical data.

The following image shows the multiple tabs for entering alarm type information:

Use this tab...	To
General	Define alarm attributes, such as the alarm type name, description, alarm state transition type and data point scan rate. Learn more
Inputs	Define alarm inputs. Inputs are a set of values and other settings, needed to create specific alarm behaviors or conditions for alarm sources (tags) that use the alarm type. You can create or designate unlimited input values. Learn more
Settings	Configure common or independent settings for conditions and field values, such as Alarm On / Off delay times, Enable / Disable Out-of-Service, Suppressed and Audible Alarm settings. Learn more
Time Triggers	Define time triggers. A specific alarm source evaluation takes place when a time-based event is triggered. Learn more Value-based data change triggers are entered in the Inputs tab.
Fields	Define alarm fields. Fields are the values sent to a client application with each alarm transition (alarm state change). Fields can be predefined fields, such as message and severity, or a custom field value where you specify the field name and data type. Learn more
Conditions	Define the alarm condition (normal or alarm state). A condition code number indicates when the alarm switches to this condition. The expression logic is matched to the condition code value to determine the state of the alarm. Use condition code zero (0) for the normal state; a non-zero code is the alarm state. Learn more Every alarm type allows you to specify any number of alarm conditions. At a minimum, two conditions must be configured—one for the normal and one for the alarm. Every condition is identified by an integer number in the range of [-1000 to1000], allowing you to specify up to 2000 alarm conditions.
Values	Review values for alarm conditions. Values, related to alarm conditions, are where you specify different values based on an active alarm. For example, you determine alarm severity such as a High-High (HiHi) value of 1000 and a High (Hi) value of 500. Learn more
Expressions	Enter alarm type expressions. Expressions are alarm evaluation logic. The expression returns an integer number or a value representing an alarm condition. An expression can be an input variable for the defined alarm type input values. For example, when a Hi alarm is generated, another expression generates the 'return to normal condition'. Learn more

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