The DDRC405 is an obsolete product and should be replaced with a DDRC420FR 

The DDRC405 relay controller is designed to operate any type of switched load. It incorporates common supply SPST output relays, suitable for ON/OFF control of all types of mains rated equipment and is especially suited to driving contactors. The device is DIN rail mountable, designed for installation within a switchboard, or next to circuit breakers feeding the circuits or contactors to be controlled. The DDRC405 can operate as a stand-alone unit or as part of an integrated system when connected to a DyNet network.