Allen-Bradley 1771-IGD PLC-5 TTL Digital Input Module | 16-Channel

Product Description

The 1771-IGD TTL input module from Allen-Bradley is part of the PLC-5 and 1771 Series I/O family. This rack-mounted module provides 16 TTL input channels with selectable positive or negative logic states, making it suitable for high-speed digital signal processing. Designed for compatibility with multiple 1771 chassis, the 1771-IGD delivers reliable performance in industrial automation systems requiring precise TTL-level input monitoring.

Technical Specifications

• Manufacturer: Allen-Bradley

• Part Number: 1771-IGD

• Product Line: PLC-5 / 1771 Series I/O

• Product Type: TTL Input Module

• Weight: 1.00 lbs (0.45 kg)

• Number of Inputs: 16 channels

• Logic State: Selectable positive or negative logic

• Signal Voltage Rating:

• Positive Logic: ON = 2.0–5.25 V DC; OFF = -0.2–0.8 V DC

• Negative Logic: ON = -0.2–0.8 V DC; OFF = -2.0–5.25 V DC

• Backplane Current Draw: 130 mA @ 5 V DC

• Power Dissipation: 0.4 W (min), 2.7 W (max)

• Signal Delay:

• DC ON: < 1 ms

• DC OFF: 20 ± 9 ms

• AC OFF: 24 ± 10 ms

• Operating Temperature: 32–131 °F (0–55 °C)

• Voltage Category: 5 V DC, TTL

• Mounting: Rack-mounted in 1771 chassis

• Compatible Chassis: 1771-A1B, A2B, A3B, A3B1, A4B (Series A or B)

• Compatible I/O Chassis: 1771-AM1, 1771-AM2

• Wiring Arm: 1771-WH

• Model Status: Earlier model, discontinued

Key Features

• 16 TTL Inputs: Supports both positive and negative logic states

• Fast Response: < 1 ms ON delay for high-speed applications

• Flexible Compatibility: Works with multiple 1771 chassis configurations

• Durable Design: Built for industrial automation environments

• Selectable Logic: Adaptable to different signal requirements

Application Scenarios

• High-speed digital input monitoring in PLC-5 systems

• Machine control requiring TTL-level signal processing

• Legacy automation systems with 1771 Series racks

• Industrial environments needing reliable TTL input modules

FAQ

Q: How many inputs does the 1771-IGD provide?  A: It supports 16 TTL input channels.

Q: What logic states are supported?  A: Both positive and negative logic states are selectable.

Q: Which chassis are compatible with this module?  A: It works with 1771-A1B, A2B, A3B, A3B1, A4B, and AM1/AM2 chassis.

Comparison with Similar Models

• 1771-IGD: TTL input module, 16 channels, discontinued

• 1771-IBD: DC input module for general digital signals

• 1771-IXD: Isolated input module for specialized applications