The Siemens 6AG1105-2AA10-4AA0 is a managed industrial Ethernet switch built for automation networks that demand deterministic failover and remote management. Its ring-redundancy feature recovers a link break within a couple of milliseconds—no spanning-tree wait, no packet loss during the transition. That alone makes it a reliable choice for ring topologies.
It runs on standard 24 V DC and draws 0.1 A maximum, so it slips into a control panel without a dedicated power supply. The IP20 enclosure and rail mount mean it fits alongside other control-panel components.