This feature is standard on both managed and unmanaged switches
(non-ECO versions). The power input connector on the switch has two
dedicated alarm circuit connections that can be wired to any warning
device, such as a PLC or pilot light. Error conditions that can be
monitored include port link failure (cable disconnect, network
disruption, for example), power supply disruption/disconnect, or power
supply voltage out of specified range. Wago Corp.www.wago.us800.DIN.RAIL