Product Overview
The Allen-Bradley 1771-IGD is a TTL input module designed for use with Rockwell Automation 1771 I/O chassis. It provides sixteen (16) inputs with selectable logic-levels, making it suitable for high-speed digital signal detection in industrial control systems. This module is compatible with Series A or B 1771-A1B, 1771-A2B, 1771-A3B, 1771-A3B1, 1771-A4B, 1771-AM1, and 1717-AM2 chassis. Whether you are upgrading an existing system or building a new one, the 1771-IGD offers reliable TTL-level input processing.
Technical Specifications Breakdown
Key parameters for the 1771-IGD are listed below for quick reference:
| Feature | Specification |
|---|---|
| Module Type | TTL Input Module |
| Number of Inputs | 16 |
| Backplane Current | 130 mA @ 5VDC |
| Signal Voltage Rating (Positive Logic) | On = 2.0 - 5.25VDC; Off = -0.2 to 0.8 VDC |
| Signal Voltage Rating (Negative Logic) | On = -0.2 to 0.8 VDC; Off = 2.0 - 5.25VDC |
| Signal Delay | Less than 1ms |
| Power Dissipation | 2.7 Watts (max); 0.4 Watts (min.) |
| Operating Temperature | 32 to 131 F |
| Wiring Arm | 1771-WH |
Industry Applications
Common uses include:
- High-speed counting and positioning: The less than 1 ms signal delay allows accurate capture of rapid pulses from encoders or sensors.
- Machine status monitoring: The 16 inputs can monitor limit switches, pushbuttons, or proximity sensors in packaging, material handling, or assembly lines.
Installation & Setup Guidance
Before installation, ensure the chassis is powered off. The module fits into any slot of a compatible 1771 chassis. Use the 1771-WH wiring arm for signal termination. For signal wiring, use 14 AWG stranded copper wire with insulation rated for 60°C and maximum insulation thickness of 3/64 or 1.2 mm. Recommended cable is Belden 8761 or equivalent. Torque each terminal to 9 lb-inch (1.0 Nm). The module has 18 LED status indicators, including a positive logic indicator and module active indicator, for quick operational status reference.
Maintenance & Reliability
Periodically inspect the module and wiring arm for signs of wear, corrosion, or loose connections. Keep the operating environment within the specified temperature range of 32 to 131 F (0 to 55°C) to ensure reliable performance. The module's power dissipation ranges from 0.4 W (min) to 2.7 W (max), so adequate ventilation in the enclosure is recommended. No user-serviceable parts are inside; if issues arise, contact technical support.
Compatibility & Integration
The 1771-IGD is compatible with Series A or B 1771-A1B, 1771-A2B, 1771-A3B, 1771-A3B1, 1771-A4B, 1771-AM1, and 1717-AM2 chassis. It uses the 1771-WH wiring arm for signal connections. The module supports both positive and negative logic, selectable via a jumper setting. By default, it is set to positive logic. To change to negative logic, move the jumper toward the front of the module. This flexibility allows integration with various TTL-level devices.
Selection Guide & Purchasing Advice
When selecting the 1771-IGD, verify that your chassis is among the compatible models listed above. This module is an earlier model, so confirm lifecycle status and availability with AutoDCSTech before ordering. AutoDCSTech offers genuine Allen-Bradley parts with expert support to help you find the right component for your application. Contact our team for pricing and stock information.
Troubleshooting & Common Issues
If the module does not power up, check the backplane connection and ensure the chassis power supply is functioning. Verify that the logic level jumper is set correctly for your application. If input signals are not detected, confirm that the signal voltage meets the specified ranges: for positive logic, ON = 2.0 - 5.25VDC and OFF = -0.2 to 0.8 VDC. Use the LED indicators to diagnose input status. For persistent issues, inspect the wiring and replace the 1771-WH arm if damaged.
Availability & Condition at AutoDCSTech
| Part Number | 1771-IGD |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
