In this example, the product information for a modular AutomationComponent that has been pre-configured with a known set of allowable modules is considered. In this example, the modular AutomationComponent consists of a head end and a number of modules that can be either attached to the head end or to slots in a chassis.

A Descriptor with product information for this modular AutomationComponent can contain the following elements:

• one or more Information Model AML files or one embedded Descriptor for the head end and chassis;
• one or more Information Model AML files or one embedded Descriptor for each module that can be attached;
• documentation and pictures.

Figure 15 shows the situation where the head end and the modules are described with Information Model files.

Figure 15 – Modular device Descriptor with AML files

Figure 16 shows the situation where the head end and the modules are described with embedded Descriptors.

Figure 16 – Modular device Descriptor with embedded Descriptors

In Figure 16, a module can also exist outside of the modular device Descriptor. In this case, there is a reference from the modular device Descriptor to the external module Descriptor.