Allen-Bradley 1746-IB32 SLC 500 Digital Input Module

The Allen-Bradley 1746-IB32 is a 32-point digital input module for the SLC 500 family that accepts 15–30 V DC sinking inputs and channels them to the backplane for the PLC to read. Designed for general-purpose DC input sensing, it supports external 24 VDC sensor or switch signals and provides 32 separate input points that can monitor a wide range of automation devices in a single slot.

• Input type and range: 32 DC inputs, 15–30 V DC sinking
• Backplane current (5 V DC logic): 103 mA
• Signal response and timing: typical input signal delay around 3 ms
• Off-state current: ≤1 mA
• Isolation and safety: 1500 V AC dielectric withstand between backplane and I/O; group isolation via 1492 terminal blocks recommended
• Mechanical and wiring: compatible with standard SLC 500 backplanes and 1492 terminal block wiring for isolated groups

Applications include machine control panels, conveyors, safety interlocks, and general process monitoring where multiple 24 V DC sensors must be read by a controller. The module slides into an SLC 500 chassis and uses a standard 1746 backplane, with 1492 terminal blocks commonly employed to maintain required group isolation across the I/O network.