Allen-Bradley 1756-IB32 ControlLogix IO Module

Allen-Bradley 1756-IB32 is a ControlLogix 32-point digital input module that provides 32 sinking 12/24 V DC inputs for the 1756 I/O backplane, operating on a 10–31.2 V DC range with a nominal 24 V input.

It arranges inputs in two 16-point groups, uses a removable terminal block (1756-TBCH or 1756-TBS6H), and supports open-style mounting with a slot width of 1. The module provides 250 V isolation between the inputs and the backplane, with no isolation between individual group inputs, and features a 5.67 kΩ input impedance at 31.2 V DC, 2 mA current draw at 24 V, and 0.66 W total backplane power (6.2 W max dissipation at 60 °C).

Timing and data features include a hardware delay of 380 µs (Off-to-On) and 420 µs (On-to-Off) with user-selectable filter times (0/1/2 ms Off-to-On; 0/1/2/9/18 ms On-to-Off), input timestamps within ±200 µs, and cyclic update times from 200 µs to 750 ms. This module is designed to integrate with the ControlLogix I/O specifications and is suitable for 24 V DC sensor/actuator networks in industrial environments, typically used for reading digital input states from field devices.