Allen-Bradley 1771-A4B Sixteen Slot PLC-5 Chassis

Allen-Bradley 1771-A4B PLC-5 16-slot I/O chassis is a back-panel-mount enclosure that provides dedicated space for up to 16 1771 I/O modules within a PLC-5 control system. The rugged steel chassis measures 298 mm high × 70 mm wide × 187 mm deep (11.75 in × 2.75 in × 7.375 in) and weighs approximately 1.4 kg (3.0 lb), making it suitable for industrial environments where compact, organized I/O racks are needed. Designed to be paired with a PLC-5 processor on a common backplane, this 16-slot chassis expands the controller’s input/output capacity while keeping wiring tidy through its back-panel mounting. As part of the 1771 I/O family used in PLC-5 systems, the 1771-A4B supports a wide range of 1771 I/O modules, enabling modular configuration for scalable automation applications and streamlined panel layout in mid‑scale control deployments.