The DDW-221 can be used to extend Ethernet networks over existing copper cables in point-to-point, daisy-chain or redundant ring applications. Point-to-point transmission distances of up to 10 km can be achieved with data-rates of 5.7 Mbit/s possible over shorter distances on a single copper pair. The redundant protocol can be used ether on the SHDSL interface or on the built-in Ethernet switch. Our unique FRNT (Fast Recovery of Network Topology) technology is the fastest protocol on the market to re-configure a network in the event of any failure of a link or hardware. The built-in 4 port Ethernet switch makes the DDW-220 the only necessary component required to create a small network. Total galvanic isolation between all interfaces, extended type approvals and rugged mechanical design as well as extensive over-voltage protection and line interface voltage suppression makes the DDW-220 the best solution in harsh industrial environments.