Network Topology¶

Information and recommendations for the topology of a control network¶

It is recommended to set up a network system so that the following are possible:

• Extensive self-configuration (address assignment)
• Transparent support for every communication medium
• Transport of data packets between different networks

The routing mechanism should be so simple that each network node can reroute data packets, even if it has a low memory capacity. Therefore, avoid extensive routing tables, complex calculations or queries at runtime.

Construct the control network hierarchically. Each node may possess a parent node and any number of child nodes. A node without a parent is a “top level” node. Cycles are not permitted, i.e. each control network has the structure of a tree.

Parent-child relationships results from the specification of certain network areas. A network area can be, for example, a local Ethernet or a serial point-to-point connection. We differentiate between the main network (mainnet) and the subnetworks (subnet). Each node belongs at the most to one main network, to which its parent node, if one exists, also belongs. For each node any desired number of subnets can be configured, for which the node acts in each case as a parent.

A network area may have only one parent node. Therefore, a configuration in which a network area is defined at the same time as a subnet of several nodes is invalid.

See also

• Addressing and Routing
• Address Structures