 | Excluding IVI-C Functions and Attributes from an Instrument Class |
When an IVI-COM driver supports a particular instrument class, all of the instrument class methods and properties are exposed to the end user, even if the driver does not support certain IVI-defined methods and properties. For IVI-COM methods exposed from the driver but not actually supported, the driver returns a specific IVI-defined error. The requirement to expose all methods and properties is a natural consequence of the interface-based programming model on which COM (and, hence, IVI-COM) is based.
With IVI-C drivers, however, functions and attributes defined in the instrument class need not be exposed from the IVI-C driver at all. Indeed, if an IVI-C driver does not support a particular IVI-defined function or attribute, then the item should not be exposed from the driver. Nimbus supplies a special command to exclude specific IVI-defined functions and attributes from an IVI-C driver.
To exclude a class-compliant function or attribute from the IVI-C driver
From Solution Explorer, double-click the Driver Designer node under the Nimbus node.
The Driver Designer opens as a tabbed document window. Choose the IVI-C tab.
Click the Hierarchical button beneath the tree view on the left side of the IVI-C Designer.
You can also work from the flat tree view of functions and attributes by clicking the Flat button beneath the tree view.
Locate the IVI-defined function or attribute that you with to exclude. Note that IVI-defined items appear with greyed text in the tree views, indicating that their definition cannot be modified.
Right-click on the function or attribute and choose Exclude from IVI-C Driver. The node now appears with a strikethrough.
Nimbus will remove the implementation code for the function or attribute. It will also remove the function or attribute from the IVI-C driver header file (.h), import library (.lib), main DLL (.dll), function panel (.fp), and attribute information file (.sub).
CautionIf you exclude an IVI-C function or attribute that is manually implemented, Nimbus will automatically delete your custom code. Be sure no code of interest remains before executing this command.
To restore an IVI-C function or attribute that has been excluded, right-click the item and choose Include in IVI-C Driver.