Allen-Bradley 1771-ID16 16-Point Digital Input Module

Allen-Bradley 1771-ID16 is a 16-point digital input module designed for PLC-5 control systems, mounting on the 1771 I/O bus and sharing the PLC-5 backplane with other input and output modules. This AC/DC isolated input module is rated for 120 V signals across its sixteen channels, enabling direct connection of commonly used industrial field devices such as pushbuttons, limit switches, proximity sensors, and other discrete sensors operating at line voltage. Each of the 16 inputs is optically isolated from the others and from the backplane to help protect the controller and minimize cross-channel interference in noisy environments. The device provides 17 indicators in total, including 16 input-status indicators that reflect real-time channel states and an additional module indicator to aid diagnostics. The ID16 uses Rockwell Automation's 1771 I/O addressing scheme and is designed to integrate with a PLC-5 processor and Rockwell's broader automation ecosystem, supporting straightforward expansion as system needs grow. Typical applications include machine control, line monitoring, interlock logic, and safety-related sensing where reliable high-voltage digital inputs are required. The 1771-ID16 is part of the broader 1771 family of I/O modules, offering a hardware-backed, field-proven solution for discrete input acquisition in legacy and retrofit automation projects.