About library objects

A library object is the class definition of an object. A library object is instantiated. Individual library object files (HSL4) are XML-formatted and registered in the

Application Code Manager

database. A library object typically defines parameters, subclasses, user interface content, and portions of controller code (for example, Logix) and HMI code (for example,

FactoryTalk® View Machine Edition (ME)

or

FactoryTalk® View Site Edition (SE)

).

Library objects contain controller code, as well as decoration (custom properties). Decoration is applied to a library object in the

Library Designer

. Decoration can be inherited from a library object that is higher in scope. Decoration applied to a library object is inherited by, or available to, all elements that are contained within the library object. Decoration can also be applied directly to an element, overriding inheritance from the library object and from library objects of higher scope.

The project library object and controller library object are added to an ACD file using separate menu commands in the

Library Designer

. The project and controller library objects are placed higher in the library object hierarchy than any Logix object library objects and have predefined parameters.

Library objects designated as modules in the

Library Designer

will be brought into

Application Code Manager

projects as hardware components rather than software components. The

Library Designer

features a module wizard that ensures that required parameters are included when the new module library object is created.

Parameters, substitutions, functions, external references, and expressions created in the

Library Designer

can be accessed, reused, and rescoped multiple times using the

Expression Builder

. Functions and expressions that are saved in the

Library Designer

become program resources and are available to all projects opened in the program. The

Library Designer

also includes a set of predefined parameters available to all projects.

The Library Designer allows for libraries to be classified by their content type. The largest granularity type would be the task type library followed by the program type library and then the routine type library. With each library type, it is possible to add content without including parent containers. As an example a task type library would include task, program and routine objects, a program type library would include program and routine type objects and a routine type library would contain routine objects. Each library type would not include parent objects. As an example a program type library would not include task type objects, programs from different tasks can be added to the same library however when this library is instantiated in

Application Code Manager

all the programs will end up under the same task. To keep all of the programs separated, make the library a task type.

Different actions can be performed on the

Library Objects

items based on where the item is in the library object structure.

This list describes the possible actions.