Configuring Alarms

Complete the following steps to configure alarms for channels.

  1. On the Home page of the Static Data Viewer, select the channel(s) from the Channel List.
  2. In the Data Table, specify a value for the HI Alarm (high) and/or LO Alarm (low) thresholds in the channel row for which you want to configure an alarm rule.
    Note The default value for alarm rules is NaN, which indicates that an alarm rule does not exist for a channel regardless of the Hysteresis and Alarm Enabled fields.
  3. Specify the Hysteresis value for the alarm threshold. Use hysteresis to reduce recurrent alarms on channels with fluctuating live values. The same hysteresis value is applied to both the HI Alarm and LO Alarm rules.
    Alarm Example Behavior
    HI Alarm is set to 2 and Hysteresis is set to 1
    • The alarm becomes active when the channel value is greater than the HI Alarm threshold.
    • The alarm becomes inactive when the channel value passes below the HI Alarm threshold minus the Hysteresis value (2 - 1 = 1). The alarm becomes inactive (not cleared) when the channel value is 1 or lower.
    LO Alarm is set to 0 and Hysteresis is set to 0.5
    • The alarm becomes active when the channel value is less than the LO Alarm threshold.
    • The alarm becomes inactive when the channel value passes above the LO Alarm threshold plus the Hysteresis value (0 + 0.5 = 0.5). The alarm becomes inactive (not cleared) when the channel value is 0.5 or greater.
  4. Select the Alarm Enabled checkbox to initiate the alarm rule evaluation.
    Tip Click Disable All to batch disable the configured alarms. To clear configured alarm values and return the values to default, you must delete the alarm rule from the Saved Alarm Rules page.
If an alarm threshold for a specific channel is met, the channel appears in the Alarms field. Click Clear to remove an alarm instance from the Alarms field. Refer to the following table for more information about alarm states.
Table 8. Alarm States
Alarm State Description
Active (Red) The alarm is active and has not been acknowledged.
Inactive (Clear) The alarm for the channel is inactive.
Active (Yellow) The alarm has been acknowledged. Click Acknowledge Alarm to acknowledge the alarm instance.