Allen-Bradley 1771-IGD TTL Input Module

General Information

• Manufacturer: Rockwell Automation

• Brand: Allen-Bradley

• Part Number / Catalog No.: 1771-IGD

• Module Type: TTL Input Module

• Number of Inputs: 16

• Voltage Category: 5 Volts DC, TTL

• DC Operating Voltage: 5.0–5.3 Volts

• Backplane Current: 130 mA @ 5 VDC

• Model Status: Earlier Model

• Wiring Arm: 1771-WH

• Mounting: Rack Mountable

Logic & Signal

• Logic State: Selectable Positive or Negative Logic

• Signal Voltage Rating:

• Positive Logic: On = 2.0–5.25 VDC, Off = -0.2–0.8 VDC

• Negative Logic: On = -0.2–0.8 VDC, Off = 2.0–5.25 VDC

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

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

• Signal Delay: <1 ms

• Typical DC Signal Delay: On <1 ms, Off 20 ±9 ms

• Typical AC Signal Delay (Off): 24 ±10 ms

• Max DC Off-State Current: N/A

Power & Thermal Specifications

• Power Dissipation: 0.4–2.7 Watts

• Thermal Dissipation: 1.4–9.2 BTU/hr

• Isolation Voltage: 1500 V AC RMS (1 second)

• Fuse Protection: 0.5 A, 250 V Normal Blow

Environmental Specifications

• Operating Temperature: 0–60°C (32–131°F)

• Humidity Range: 5–95% non-condensing

Overview

The Allen-Bradley 1771-IGD is a high-performance TTL input module from the 1771 Product line, offering sixteen 5 V DC TTL current-sourcing inputs. It requires a customer-supplied 5 V DC power source with ±0.25 V and less than 50 mV peak-to-peak ripple.

The module supports selectable logic states. By default, it operates in positive logic, detecting Logic 1 (On) at 2.0–5.25 V DC and Off at -0.2–0.8 V DC. Negative logic can be configured via jumper settings, reversing the On/Off voltage ranges.

Designed for compatibility, the 1771-IGD works with Series A or B 1771-A1B, 1771-A2B, 1771-A3B, 1771-A3B1, 1771-A4B chassis, as well as 1771-AM1 or 1771-AM2 I/O chassis. Signal termination requires the 1771-WH wiring arm and 14 AWG stranded copper wire, with a maximum insulation thickness of 3/64 inch (1.2 mm). Recommended cable: Belden 8761 or equivalent, with terminal torque of 9 lb-in (1.0 N·m).

The module provides fast input response (<1 ms), reliable thermal and power dissipation, and includes 18 LED indicators for quick monitoring of module and logic status. With a robust design, the 1771-IGD ensures accurate and reliable TTL input performance in industrial environments.