Interfaces(plug-type connectors) can be described for a system on the one hand and for part types of components on the other. They are described in the item <Interfaces> by part type. Interfaces can not be described for parts, because a part inherits the interfaces from the respective part type (Part and part type belong to the same part definition in this case.).
Interfaces and ports can be identified by a <drawing-number> and a <part-number> or a reference(<part-type-ref>) to a interface <part-type>. The interface can be classified with <interface-class>. The class values can be defined company specific. Further the <seal>, a short description(<desc>) and a extented description (<ncoi-3>) can be defined for a interface.
<interface>s can contain modules and one or more ports which can be grouped together with<port-group>s . The <ports> within a <port-group> can be defined as electrical, pneumatic, hydraulic or optical ports with the attribute [kind]. The default value is "electric". One interface can, for example, contain electrical ports and also pneumatic ports. Each <port> has an attribute [direction] which can be set to the values in, out, bi, ground, power-supply or other. Generally all ports exist in each variant The reference <variant-def-ref> is only used to exclude <port>s from specific variants.
The following figure illustrates the situation:
Figure 5: An example of interfaces
In the ABS system, there are the parts (employed part types) control unit and hydraulic aggregate. The system has two interfaces; these are described by ABS part type under the item <architecture>/<interfaces>. The interfaces on the parts are inherited from the respective part types and are therefore described in the part type specifications under the item <architecture>/<interfaces>(for the part type, not for the part!) as well.
Interfaces can be connected to other <part-types> either with or without harness. This can be defined in the attribute [connection-type] with the values "harness" or "no-harness". The default value is "harness" which mean that a separate <part-type> exists and the <port-number>s of the interface are the port-numbers of the interface itself. If the value "no-harness" is set, no <part-type> "harness" exists and the <port-number>s are the port-numbers of the connector at the harness.
If a part-type has a interface that is visible from the outside of the part-type but isn't mounted physically on itself, the real interface can be linked with <interface-ref>. That is there is a temporary interface on the surrounding <part-type> that references to the interface which is mounted on the integrated <part-type>.