Genius DC Discrete I/O blocks (IC660BBD022) interface to a wide range of input devices, including both 2-wire and 3-wire electronic proximity switches. Outputs may be low-power control and indicating devices such as relays, contactors, and lamps. These blocks have identical discrete I/O circuits, each easily configured to be an input or an output. The IC660BBD022 consists of IC660EBD020 AND IC660TBD022