Below there are a few examples that go over the differences with using specific modules to route the connection. Note that typically, the end result PLC does not matter. So while the example may show connecting to a PLC5 through ControlNet, the the PLC5 could easily be swapped out with another PLC, and the connection path would remain the same. The big change when using different end result PLCs is what device driver to use for the connection.
Understanding how the Connection Paths are built listed above is important to understand the specifics of using different modules in the examples below.