1771-IGD Input Module – Selectable Logic TTL for 1771 Chassis

1771-IGD TTL Input Module

Brand: Allen-Bradley | Series: 1771 | Type: TTL Input Module

The 1771-IGD is a 16-point 5V DC TTL input module for the 1771 chassis series. It supports selectable positive/negative logic and delivers fast signal detection (<1 ms). Ideal for PLC-5 systems requiring high-speed digital interfacing.

Technical Overview

• Inputs: 16 (TTL, current sourcing)
• 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
• Signal Delay: On < 1 ms ; Off ~ 20 ms (typ.)
• Backplane Current: 130 mA @ 5 VDC
• Power Dissipation: 0.4 W (min) – 2.7 W (max)
• Thermal Dissipation: 1.4 – 9.2 BTU/hr
• Isolation: 1500V AC RMS (1 sec)
• Fuse: 0.5A / 250V (normal blow)
• LEDs: 18 status indicators (active + logic state)

 Compatible Chassis & Mounting

• 1771 Series A/B: 1771-A1B, A2B, A3B, A3B1, A4B
• I/O Chassis: 1771-AM1, 1771-AM2
• Wiring Arm: 1771-WH (required)
• Wire Size: 14 AWG stranded copper, 60°C insulation
• Recommended Cable: Belden 8761 or equivalent
• Torque: 9 lb-in (1.0 N·m)

 Installation & Environment

• Operating Temp: 32–131 °F (0–60 °C)
• Supply Voltage: 5.0–5.3 VDC (Class 2, max ripple 50 mV)
• Input Current (source): 7 mA max per input
• Input Current (sink): 0.8 mA max per input
• Default logic is positive; move jumper toward front for negative logic.

 Oiltech Controls’s Insight

• This module is a workhorse for PLC-5 systems needing clean TTL interfacing.
• Selectable logic makes it versatile for both active-high and active-low devices.
• Low power dissipation (0.4W min) allows dense chassis configurations.
• Fast on-delay (<1 ms) is critical for high-speed counting or positioning.

 Suitable Equipment

• PLC-5 programmable controllers
• High-speed counter modules (1771 series)
• Motion controllers requiring TTL level inputs
• Legacy automation systems with 5V logic
• Industrial sensors and encoders with TTL output

 5 Professional FAQs

• Q1: Can I mix positive and negative logic on different inputs?
  A: No. The jumper sets the entire module to either positive or negative logic for all 16 inputs.
• Q2: What happens if I exceed 5.25V on an input?
  A: The input may be damaged. Use a voltage divider or level shifter to keep within 5.25V max.
• Q3: Which chassis are fully compatible?
  A: Series A/B 1771-A1B, A2B, A3B, A3B1, A4B, plus 1771-AM1 and AM2.
• Q4: How do I choose between positive and negative logic?
  A: Check your sensor/device output. If it sources current when active, use positive logic. If it sinks current, use negative logic.
• Q5: Is the 1771-WH wiring arm included?
  A: No, it is sold separately and is mandatory for field wiring.

Why Buy From Oiltech Controls?

• Over 15 years in industrial automation spares – we know legacy systems.
• Global shipping via FedEx, UPS, DHL – 24-28 hour dispatch.
• All units are tested (surplus/refurbished) before shipment.
• 12-month warranty for peace of mind.
• Technical verification ensures plug-and-play reliability.
• Expert support for obsolete control systems – we keep you running.

Shipping: Worldwide delivery with FedEx, UPS, or DHL. Orders ship within 24–28 hours.

Contact: info@oiltechcontrols.com | +86 158 8020 0923

Copyright © 2026 Oiltech Controls Limited. https://www.oiltechcontrols.com/ All rights reserved.