Configuring Hysteresis

Specify a threshold above or below the severity level that sets an alarm to reduce alarm instances from a noisy signal.

Before you begin, configure a trend alarm rule. Configuring hysteresis is useful for preventing an alarm from clearing immediately after it is set. To learn more about hysteresis, refer to Conditions of Setting and Clearing Alarms. Specify an offset value from the Compare To value that clears an alarm.

1. Click the Navigation menu and go to Alarms» Trend Rules .
   
2. Find and select the trend rule for which you want to configure hysteresis.
3. Click Edit to bring up the Trend Alarm Rule dialog.
   
4. Below the sample of data in the dialog, configure the hysteresis value in the Hysteresis text field.
5. Click OK.
   

The alarm rule that you have modified now clears an alarm when trend values cross the threshold for the hysteresis you specified. If you want to refine the conditions for setting an alarm further, consider configuring an on and off delay.