Allen-Bradley 1756-IA32 ControlLogix IO Module

The Allen-Bradley 1756-IA32 ControlLogix AC input module is a 32-point digital input card for the ControlLogix I/O backplane that accepts 74–132 VAC signals (47–63 Hz) and provides 32 discrete inputs for field devices. It supports diagnostic status in groups of four, offering 8 groups of 4 diagnostic points for health monitoring. Electrical characteristics include operating voltage 74–132 VAC (nominal 120 VAC), input impedance up to 14 kΩ at 132 V AC / 60 Hz, off-state voltage max 20 V, off-state current max 2.5 mA, and on-state current range of 5–15 mA depending on input voltage (74–132 VAC). Maximum power dissipation is 6.1 W at 60 °C, with internal current draw of about 165 mA at 5.1 V and 2 mA at 24 V. Input response delays follow the data sheet: OFF→ON delay 1.5 ms nominal, 10 ms max with a user-selectable input filter time of 1 or 2 ms; ON→OFF delay 1 ms nominal, 8 ms max with a user-selectable filter time of 9 or 18 ms. This module is designed for use in standard ControlLogix racks and communicates via the 1756 I/O backplane, making it suitable for digital input sensing on AC-powered field devices in industrial automation systems.