Wireless 2.4 GHz FHSS SpreadSpectrum Radio Long-range SRM6330 Ethernet SRM6130 Serial CIX6500 Protocol to I/O & I/O to I/O System CIX6535 Protocol Master CIX6530 I/O Remote or I/O to I/O PlantLinc Medium-range PLR6330 Ethernet PLR6130 Serial PLR6500 Protocol to I/O & I/O to I/O Systems PLR6535 Protocol Master PLR6530 I/O Remote or I/O to I/O