Introduction
Use a daisy chain loop network configuration that implements the RSTP service to establish redundant communications with at least one of the two physical paths between:
the I/O scanner
the adapter modules at each remote drop, dual ring switches (DRSs), or any product that has the capacity to be RIO scanned
For network topology planning, refer to your system planning guide.
NOTE: Fiber optic ports are not available on
the adapter modules. For fiber optic support use either a BMXNRP020• optic fiber conversion module
or a pair of DRSs.
RIO Simple Daisy Chain Loop
The CPU supports communications with RIO drops in a daisy chain loop:

1 main local rack with a BME•58••40 CPU with the Ethernet I/O scanner service
2 X80 RIO drops with a BM•CRA312•0 adapter module
3 the daisy chain loop