Allen-Bradley 1771-IBN 32-Channel DC Input Module

Allen-Bradley 1771-IBN Digital DC Input Module

Product Introduction

The Allen-Bradley 1771-IBN is a high-density discrete input module from the 1771 product family. This module provides thirty-two (32) sinking input channels that accept a 10-30VDC operating voltage range. It is specifically designed for PLC-5 systems and interfaces with field devices like pushbuttons, selector switches, and proximity sensors.

Furthermore, the 1771-IBN module offers excellent noise immunity with its built-in digital filter. This filter delivers a typical signal delay of 6 ms (±2 ms) for both ON and OFF transitions. Additionally, each channel has a dedicated red LED indicator on the front panel. This feature allows for immediate visual confirmation of each input's status.

For installation, this I/O module fits into 1771 chassis such as the 1771-A1B through 1771-A4B models. It supports 1/2-slot and 1-slot I/O addressing, giving you flexible system configuration options. Moreover, the module includes optoelectrical isolation to protect your PLC backplane from electrical transients.

Technical Specifications

The 1771-IBN module operates within a 10 to 30VDC range, making it suitable for most standard DC control circuits. Its minimum on-state voltage is 10VDC, while its maximum off-state voltage is 5VDC. This clear threshold ensures reliable signal detection in industrial environments.

Specifically, the module's input delay is 6 ms (±2 ms) for both low-to-high and high-to-low transitions. This digital filtering effectively debounces noisy switch contacts. Furthermore, the module draws a backplane current of 280 mA at 5V DC. Its maximum power dissipation is 16.4 Watts, with thermal dissipation reaching 53.3 BTU/hr maximum.

The maximum off-state current is specified at 1.7 mA. This low leakage current prevents false triggering from sensor leakage. Additionally, the Allen-Bradley 1771-IBN uses a 32-bit register that directly represents each of its 32 input channels. This direct mapping simplifies programming and troubleshooting within the PLC data table.

Mechanical & Environmental Data

This input module is built for industrial durability. Its compact dimensions are 3.5 x 6.5 x 2.0 inches (89 x 165 x 51 mm), occupying a single slot in your I/O rack. The module features a conformal coating that protects its circuitry from moisture, dust, and chemical contaminants.

Moreover, the included wiring arm (catalog number 1771-WN) uses screw terminals with a recommended torque of 1.0 N-m. For wire selection, use 0.25-2.5 mm² (22-14 AWG) solid or stranded copper wire. Additionally, ensure the wire has an insulation rating of 75°C or greater. The maximum insulation thickness should not exceed 1.2 mm (3/64 inch).

The removable wiring arm significantly simplifies maintenance. If the 1771-IBN module ever needs replacement, you can detach the wiring arm and keep all field wires connected. Then, simply attach the arm to the new module—no rewiring required. This feature reduces downtime and eliminates wiring errors during module swaps.

Installation Guidelines

Installing the Allen-Bradley 1771-IBN is straightforward. First, ensure your 1771 chassis is powered off. This module is compatible with 1771-A1B through 1771-A4B chassis models. Next, select an empty slot and insert the module firmly into the backplane.

For correct positioning, the keying bands should be placed between pins 18 and 20 on the upper connector. Similarly, they should be positioned between pins 14 and 16 on the lower connector. This keying prevents incorrect module insertion, protecting both the module and the chassis.

After securing the module, attach the pre-wired 1771-WN field wiring arm. Finally, apply power to the chassis and verify that the green status LED illuminates. Each of the 32 red input LEDs will then indicate the corresponding channel's signal state.

Front Panel Indicators

The front panel of the 1771-IBN features an impressive array of 32 red LED status indicators. Each input channel has its own dedicated LED. This allows for quick, at-a-glance diagnostics and troubleshooting. Additionally, a green status LED provides visual confirmation of the module's overall operational health.

Packaging List

• 1 x Allen-Bradley 1771-IBN Digital DC Input Module

• 1 x 1771-WN Field Wiring Arm

• 1 x Installation Instructions Sheet

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Frequently Asked Questions (FAQ)

1. What is the operating voltage range for the 1771-IBN module?
The 1771-IBN module has a DC operating voltage range of 10 to 30 Volts.

2. Which 1771 chassis are compatible with this module?
This module is compatible with 1771-A1B through 1771-A4B chassis models.

3. How many input channels does the 1771-IBN have?
It has thirty-two (32) input channels, organized as four sets of eight channels each.

4. Can I replace the 1771-IBN module without rewiring?
Yes, you can. The module includes a removable 1771-WN wiring arm. Simply detach the arm from the old module and attach it to the new one.

5. What is the input delay time for the Allen-Bradley 1771-IBN?
The typical signal delay is 6 ms (±2 ms) for both ON and OFF transitions, thanks to its digital filtering.