The rate of change (ROC) alarms feature
- Last UpdatedDec 17, 2024
- 2 minute read
Select the ROC alarms Feature to add and configure a Rate of Change (ROC) alarm on an attribute of Integer, Float, or Double data type. You can add a ROC alarm Feature to a template or instance. If added to a template attribute, the ROC alarm Feature is automatically locked in derived objects. ROC alarm Features cannot be added to attribute arrays.
You can enable up to two categories of ROC alarms. When enabled, alarms will be triggered when the value reaches the configured limit.
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Up: Rate of increase
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Down: Rate of decrease.
For each ROC alarm, specify the following parameters:
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ROC Alarms Feature Parameters |
Description |
|---|---|
|
Limit |
The limit that the attribute rate of change value must exceed to trigger an alarm. Enter the limit value for each enabled alarm category. The down limit is a positive value, but indicates a negative rate of change, or a descending rate Hi limit. |
|
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. This text string appears in the InTouch alarm view. |
|
Changes per |
Select a unit of time for the rate of change calculation – seconds, minutes, hours, or days. |
|
Evaluate every |
The time interval, in milliseconds, at which the rate of change calculation and detection is performed. |
For additional information, see Configure rate of change alarms.