Allen-Bradley 1756-IB32 32-Point Digital Input Module

The Allen-Bradley 1756-IB32 is a ControlLogix 32-point digital input module that provides DC inputs in two 16-point banks with a shared common for reading field signals in the 10–31.2 VDC range. It accepts 24 VDC nominal inputs and specifies an on-state voltage range of 10–31.2 VDC, with an on-state current of about 4.8 mA at the low end (10 V) up to 5.5 mA at 31.2 V, an input impedance of 5.67 kΩ, and an off-state voltage limit of 5 V with a maximum off-state current of 2.27 mA. The module’s power dissipation is up to 6.2 W at 60°C, with backplane current of 120 mA at 5.1 V and 2 mA at 24 V (roughly 0.66 W backplane power and about 21.1 BTU/hr thermal dissipation). Timing and diagnostics include programmable Off-to-On delays of 0, 1, or 2 ms (hardware delay up to 380 µs) and On-to-Off delays of 0, 1, 2, 9, or 18 ms (hardware delay up to 420 µs), plus software-configurable change-of-state diagnostics and input timestamping accuracy within ±200 µs, and a short/inrush current limit of 250 mA peak decaying to 37% in 22 ms. The 32 inputs are arranged as two 16-point groups, and the module uses removable terminal blocks (typical 1756-TBCH or 1756-TBS6H) for field wiring, making it a standard 1756 I/O option within Rockwell Automation’s ControlLogix ecosystem.