Associated with: Analog and Counter-type points that support this feature
This pick action is only available on a point on which:
- The Tune Limits feature is enabled
- Your User Account is allocated the Tune Limits security permission
- The point’s alarm limits are not configured to vary in value according to Time Profiles. (With points on some drivers, you can associate individual limits with Time Profiles. Any limits that are assigned Time Profiles will not be displayed in the Tune Alarm Limits window. If all of a point’s limits are assigned Time Profiles, the Tune Alarm Limits pick action will not be available for that point.)
Use the Tune Alarm Limits action to temporarily alter a point’s alarm limits during exceptional circumstances. For instance, in bad weather conditions when a flood situation is known to exist, you might want to tune a point’s limits to stop unnecessary alarms from being raised.
Select the Tune Alarm Limits pick action to display the Tune Alarm Limits window.
The window indicates the limits that are currently in force. The number of limits varies, depending on the type of point. For analog points, ClearSCADA displays the point’s full range of values in parentheses on the right-hand side of the window. The point's full range is defined in the Alarm Limits section of the point's form. The labels used on point forms for the range fields vary between drivers. For example, Zero Scale to Full Scale or Underrange to Overrange.
NOTE: The Alarm Limits can appear as a grouping on the point form or as a separate tab, depending on the driver. For more information about a driver’s Alarm Limits, see the documentation for the relevant driver.
Select the check boxes of those limit(s) that you want to tune and then specify the required temporary limits in the adjacent fields. Specify values that are within the range that is configured for the point.
Tuning does not change the values of the alarm limits on the point’s configuration Form.
When tuning is in force:
- An entry is logged in the Event Journal, listing the temporary limits. (Any limits that are profile-controlled, and therefore not tuned, are indicated by the word ‘Profile’.)
- An additional Alarm Limits status attribute is included on the point’s Status display.
- ClearSCADA downloads the tuned configuration to the outstation on which the point is located (providing configuration downloads are supported).
- ClearSCADA compares any change in point value to the temporarily tuned limits, rather than the limits that are configured on the point’s configuration Form. Events and/or alarms are only generated if they exceed the tuned limits and take into account any Hysteresis or Persistence settings.
To remove any tuning, display the Tune Alarm Limits window and clear all of the check boxes. An entry will be logged in the Event Journal, stating that the Alarm Limits have been returned to their configured defaults.
NOTE: If using this pick action with the Automation Interface, you need to specify the method name TuneLimits.
Also see Tune M/S Alarm Limits.
Further Information
Specify any Alarm Limit Profiles in the ClearSCADA Guide to Core Point Configuration.