Note: There is a newer version of this specification see VEC 2.0.2
A ConnectionSpecification is intended to contain the logical information that is usually included on an electrical system connection plan (system schematic). It can either stand alone or detail the information of a NetSpecification. A ConnectionSpecification is a container for various ComponentNodes, Connections and ConnectionGroups. A ConnectionSpecification is used, if requirements for realization of the network should be specified (e.g. should a Net be realized with a single or multiple connection (BUS-Systems)).
Note: Logical information means a ConnectionSpecification doesn’t contain layout information. Layout information can be exchanged by other formats like SVG, PDF or DXF.
A ComponentNode is a representative for an element in the electric system, e.g. an actuator, a sensor, an ECUs. In this way it is quite similar to a NetworkNode and may even reference the corresponding NetworkNode in this case. Moreover, a ComponentNode can define childNodes in order to describe its internal structure.
Note: If inliners are introduced in a ConnectionSpecification which is intended to be a refinement of a NetSpecification the affected Nets will be divided into several Connections referencing the same Net.
A ComponentNode can specify various ComponentPorts. Each ComponentPort can reference its corresponding NetworkPort (if it has one).
Connections represent the physical realization of a Net (without a topology). A Net (e.g. the BODY-CAN-BUS) can be realized by one or more physical connections (e.g. a CAN-BUS is normally realized by two physical connections (HI & LOW)). The Connections do not define a topology of the realization. This means that a can Connection with three ConnectionEnds can be realized in different ways (e.g. three wires with splice, two wire with a double contact).
Note: There may be use cases for a ComponentNode referencing a certain NetworkNode and at the same time specifying more ComponentPorts than the referenced NetworkNode specifies NetworkPorts. An example might be the intent to specify configuration dependent Connections in combination with the wish that the relevant Connections them self, do not have to reference VariantConditions.
A Connection specifies an ordered set of two or more ConnectionEnds in which each references a certain ComponentPort.
A ConnectionGroup references two or more Connections expressing the physical realization of the referenced Connection shall be somehow grouped e.g. twisted. For complex structures a ConnectionGroup can specify subgroups. Finally, a ConnectionGroup can reference a NetGroup in order to express a refinement-relationship.