Allen Bradley I/O Scanner/Message Handling, CAT # - 1775-S4B

Allen Bradley I/O Scanner/Message Handling, CAT # - 1775-S4B. The 1775-S4B scanner fits into the PLC-3 processor chassis. On the front edge you can find pass and fail indicators, thumbwheel switch, I/O channel status indicators, backup connector, channel 5 connector, and a terminal swing arm.