Allen Bradley 1771-IAN PLC-5 Digital AC/DC Input Module

Product Overview

The Allen Bradley 1771-IAN serves as a high-density discrete interface for the PLC-5 platform. This module senses the On/Off status of field devices such as limit switches, pushbuttons, and proximity sensors operating at a 120V nominal voltage. By providing 32 input points in a single-slot format, the 1771-IAN maximizes I/O density within the 1771 Universal I/O chassis. We supply this module as 100% Brand New and Factory Original, ensuring your legacy control architecture maintains peak performance with pristine, zero-hour hardware.

Technical Specifications

The 1771-IAN utilizes an optimized circuit design to convert high-voltage field signals into logic-level data for the backplane:

Engineering Advantages

• High-Density Cabinet Optimization: The 32-point architecture allows engineers to double the input capacity of a standard 1771 chassis compared to traditional 16-point modules. This eliminates the need for additional chassis or remote I/O racks in hardware-intensive applications.

• Versatile AC/DC Sensing: The internal opto-isolation circuitry accepts both AC and DC signals within the 120V category. This flexibility permits the integration of diverse field devices onto a single module, simplifying wiring layouts and reducing spare parts inventory.

• Robust Signal Filtering: Integrated RC filtering and hardware delays suppress electrical noise and contact bounce common in industrial environments. This ensures the PLC processor receives clean, debounced state transitions, preventing logic errors during motor starts or high-voltage switching events.

• Grouped Isolation Logic: The module organizes inputs into four isolated groups of eight. This configuration allows the use of different power phases or separate power sources for each group, providing a layer of protection against localized circuit failures and ground loops.

FAQs

• Is the 1771-IAN unit truly brand new?

  Yes. We guarantee this unit is 100% Brand New and ships in its original factory-sealed Allen Bradley packaging. We do not provide refurbished or used surplus modules, ensuring you receive the full industrial lifespan and factory-tight tolerances.

• Can I use the 1771-IAN with a PLC-2 or PLC-3 system?

  Yes. The 1771-IAN is compatible with any 1771 Universal I/O chassis, meaning it functions correctly with PLC-2, PLC-3, and PLC-5 controllers, provided the chassis backplane power supply can meet the 280 mA current requirement.

• Which wiring arm must I use for installation?

  This module requires the 1771-WN wiring arm. The wiring arm allows you to replace the module without disconnecting the field wires, significantly reducing maintenance downtime.

• How does the module handle leakage current from solid-state sensors?

  The 1771-IAN features a maximum Off-state current threshold of 3.0 mA (AC). If your field sensors (such as certain 2-wire proximity switches) exhibit leakage current higher than this value, you must install a bleeder resistor across the input to prevent "false-on" signals.