Features inheritance

You can add Features to attributes that are in either derived templates or in instances. You cannot add Features to attributes in Base templates. The following parent-child object characteristics also apply to Features added to objects:

• If you add a Feature to an attribute in a derived template that has objects derived from it, all child objects inherit the Feature.

• You cannot add a Feature to attributes on derived objects that duplicate parent object Features in name and type.

• You cannot add a Feature with the same name as an existing Feature.

• Renaming a Feature on an attribute in the template to which it was originally added renames all other objects derived from the template. This change happens when the template is checked in.

• You can check in a template with an attribute configured with a new Feature with the same name as an existing Feature on an attribute in a derived object. The template definition of the Feature overrides the Feature in the derived object.

• If you remove a Feature on an attribute from a template, that Feature is removed from any child object. You see the change when you check in the template.

To create and associate a Feature with an object

1. On the Attributes page, select an attribute from the Attributes List. The available Features change to the Features allowed for the attribute.

2. Select the button for the Feature you want to apply to the selected attribute. The associated parameters for each kind of Feature become available. For detailed information about each item on the Attributes page, see About the attributes page.

3. Select the parameters for the Feature you have added. Available Features, which vary depending on the attribute’s Data Type and Writeability, are the following:

   • I/O: For information about adding the I/O Feature, see The I/O Feature.

   • History: For information about adding the History Feature, see The History feature.

   • Limit alarms: For information about adding a Limit alarm Feature, see The limit alarms feature.

   • ROC alarms: For information about adding a Rate of Change (ROC) alarm Feature, see The rate of change (ROC) alarms feature.

   • Deviation alarms: For information about adding a Deviation alarm Feature, see The deviation alarms feature.

   • State alarm: For information about adding a State alarm, see The state alarm feature.

   • Bad Value alarm: For information about adding a Bad Value alarm, see The bad value alarms feature.

   • Statistics: For information about adding a Statistics Feature, see The statistics feature.

   • Log change: For information about adding a Log Change Feature, see Use the log change feature.

4. Lock the values, if needed. The lock symbol is available only when you are working with a template. If you are working with an instance, it shows the lock condition of the value in the parent object.

5. Set any security for the attribute. For more information about setting security, see Set object security.

6. Save and close the Object Editor to include the new Features in the configured object.