|Latest Commit||Review disclaimer removed||2022-03-01|
|KBLFRM-1134||Added overview for electrological layers||2021-11-16|
The VEC offers three layer, each representing a level of abstraction for describing electrologic. This is illustrated in the diagram on the right side (Figure 1).
The Architectural Layer defines the connectivity / communication links (see Net) between components, without making any specifications regarding the physical realization. For example, this layer can be used to define which Bus technologies used by E/E components and the network topology to communicate with each other. To describe this layer in the VEC, the NetSpecification and its subelements are used.
The System Schematic Layer is more detailed than the Architectural Layer. The electrological realization of the Nets from the Architectural Layer are defined. Nets from Architectural Layer are realized by Connections. A connection has a defined electrical potential (see Signal). For example a “Body CAN Bus”, represented by a single Net in the Architectural Layer, has the two electrical potentials, “Body CAN High” and “Body CAN Low”. In the System Schematic Layer those are represented by two individual Connections.
However, the System Schematic Layer does not define a specific physical realization of the connectivity. A Connection with three ends (like in the diagram on the right) could be realized in many ways (e.g. a splice, a distribution component (star link), a double crimp, an IDC connection, …). To describe this layer in the VEC, the ConnectionSpecification and its subelements are used.
The Wiring Layer specifies a concrete physical realization of the layers above and narrows their degrees of freedom. It is getting more concrete (e.g. it defines the realization of the connection with three ends from the diagram on the right by a splice). Typically the Wiring Layer contains information such as wire colors, cross section areas, conductor and plating materials.
Due to its similarity, the Wiring Layer uses the same basic model elements as the definition of concrete harness. However, the flexibility of the VEC model allows the Wiring Layer to leave aspects unspecified. For example, by using PartUsages instead of PartOccurrences, partial WireSpecifications can be used instead of concrete PartVersions to describe the wiring. This makes it possible, for example, to define wire cross-sections and colors without having to specify insulation materials.
Many processes define documents that are similar to this layered structure in terms of their content, but do not correspond to it one hundred percent. This means, for example, that a process document “System Schematic” might contain many aspects of the VEC layer “System Schematic”, but can also define additional information from the VEC Layer “Wiring”.
This is perfectly valid and an intended feature of the VEC.