900 MHz FHSS Wireless 900 MHz FHSS SpreadSpectrum Radio Long-range SRM6230 Ethernet SRM6030 serial CIX6400 Protocol to I/O & I/O to I/O System CIX6435 Protocol Master CIX6430 I/O Remote or I/O to I/O PlantLinc Medium-range PLR6230 Ethernet PLR6030 serial PLR6400 Protocol to I/O & I/O to I/O Systems PLR6435 Protocol Master PLR6430 I/O Remote or I/O to I/O