Legend:

1 The service port on the controller connects the RIO main ring and distributed equipment (RTU devices, IEC 60870 devices, HMI) to the Ethernet control network.

2 RIO main ring (Dual-ring switches connect the local rack to an RIO drop.)

3 A BMENOR2200H module has a RS232/RS485 connection to RTU Serial devices.

4 A BMENOC0301 module on the local rack connects distributed equipment (RTU devices, IEC 60870 devices, HMI) to the RIO main ring.

5 A BMENOS0300 module on an RIO drop connects distributed equipment (RTU devices, IEC 60870 devices, HMI) to the RIO main ring.