8 Port Redundant Ring Switch. Can Satisfy the Requirement for Link-Loss-Backup in Industrial Field Applications. Supports Versatile Topologies. Equipped with 2 Power Inputs that are Redundant for Each Other. Relay Output Facility Can Deliver a Warning Signal due to Power Failure or Link Loss. With the Support of Modbus TCP Protocol, Administration of Ethernet LAN can get information from RS-408 of individual port status.