Limit alarms
- Last UpdatedApr 08, 2026
- 2 minute read
Select the Limit alarms feature to add limit alarms to an attribute of integer, float, or double data type. If added to a template attribute, limit alarms are automatically locked in derived objects. Limit alarms cannot be added to attribute arrays.
You can enable up to four categories of limit alarms: LoLo, Lo, Hi, and HiHi. When enabled, alarms will be triggered when the value reaches the configured limit.
For each limit alarm you enable, configure the following parameters:
|
Alarm parameters |
Description |
|---|---|
|
Limit |
The limit that the attribute value must exceed to trigger an alarm. Enter the limit value for each enabled Limit alarm category. |
|
Priority |
A numeric value for the urgency of the alarm. Valid values are 1 through 999, with 1 being the most urgent. For more information about pre-configuring alarm priorities, see Configure priority ranges for alarm historization, mapping, and shelving. |
|
Alarm message |
Browse and select an existing attribute or type a text string as an alarm message to be shown at runtime. |
|
Alarm deadband |
The amount, in engineering units, that the PV must be above the configured minimum Lo or LoLo setpoint, or be below the configured Hi or HiHi setpoint before an active alarm is reset to normal state (RTN). |
|
Time deadband HH:MM:SS.ssssss |
The amount of time that must elapse after the PV passes the set limit before an condition alarm is raised. |
For additional details, see Configure limit alarms.