Allen-Bradley 1746-IB32 32-Point Digital Input Module

The Allen-Bradley 1746-IB32 is a 32-point digital input module for the SLC 500 system that provides 24V DC sinking inputs. It is designed to plug into a 1746 backplane and reads signals from 24V sensors such as pushbuttons, limit switches, and proximity devices, making it ideal for discrete input applications on small to mid-size automation lines. The module is organized as two 16-point input groups, each with its own common, and is typically wired with a compatible terminal base (for example, a 1492 base) to maintain group isolation and simplify field wiring. Its operating voltage range is specified as 15–30V DC, with sinking inputs meaning the associated sensor or device connects to +24V and the module sinks current to the common when the input is active. Common applications include machine interfaces, safety interlocks, and process monitoring where reliable 24V sensing of binary signals is required. As part of Allen-Bradley’s 1746 I/O family, the IB32 shares the SLC 500 backplane interface, ensuring compatibility with standard 1746 racks and scanners and straightforward integration into existing SLC 500 control architectures. This module delivers a robust, low-profile solution for expanding digital input capability in compact PLC installations while preserving clear, maintainable wiring and scalable I/O topology.