The EKI-1511X and EKI-1512X are serial device servers which connect RS-422/485 serial devices, such as PLC, meters, and sensors to an IP-based Ethernet LAN. They allow nearly any device with serial ports to connect and share an Ethernet network. EKI-1511X and EKI-1512X provide various operation modes: COM port redirection (Virtual COM port), TCP server, TCP Client, and UDP mode. With COM port redirection mode, standard serial operation calls are transparently redirected to the EKI-1511X and EKI-1512X, guaranteeing compatibility with legacy serial devices and enabling backward compatibility with existing software. With TCP server, TCP client and UDP modes, the EKI-1511X and EKI-1512X ensure the compatibility of network software that uses a standard network API. Moreover you can make serial devices communicate with other devices peer-to-peer, without any intermediate host PCs and software programming. With a compact and slim IP30 metal case, EKI-1511X and EKI-1512X can be installed into a field cabinet easily. EKI-1511X and EKI-1512X provide terminal block connector for RS-422/485 that user can setup the physical wiring without any manually made connector. And with EMC level 3 protection, EKI-1511X and EKI-1512X can work in harsher working environments than other serial device servers.