US Patent 9294604 Serial wrap-around redundancy system

A network system includes a first data source device with a primary interface and one or more second data source devices with a secondary interface disposed in electrical communication with the first data source device. A common data source device communicates with the first data source device and the second data source device(s). A serial string with a backbone is electrically connected to the primary interface and to the secondary interface. At least one endpoint device is electrically connected to the backbone via an endpoint interface. The primary interface is constructed and arranged initially as a master communication source for the serial string. The secondary interface is constructed and arranged to monitor messages transmitted by the primary interface and to take over as the master communication source if the secondary interface does not detect messages from the primary interface after a predetermined amount of time.