3.1.4 Topology
The OPCMBTCP features a build-in Ethernet-switch, thus having two Ethernet RJ-45 connectors. This enables the possibility for connecting several Modbus TCP
options in a line topology as an alternative to the typical star-topology.
The two ports are equal, in the sense that they are transparent for the option. If only one connector is used, either port can be used.
Illustration 3.2: Star topology
Illustration 3.3: Line topology
NB!
For line topology please refer to section: “Recommended design rules” In a line topology all drives must be powered, either by mains or by their 24 V DC option
cards, for the build-in switch to work.
Modbus TCP
10
3