Allen-Bradley 1771-IGD TTL Input Module for PLC-5 Systems The Allen-Bradley 1771-IGD is a 16-point TTL (Transistor-Transistor Logic) input module designed for integration with PLC-5 systems. It facilitates the reception of low-voltage digital signals from field devices, ensuring efficient data processing and control within industrial automation environments. Key Features Input Channels: 16 TTL-compatible inputs Operating Voltage: 5.0 to 5.3 V DC Logic Level Selection: Configurable for positive or negative logic via an onboard jumper Signal Delay: Less than 1 millisecond, ensuring prompt response to input changes Backplane Current: 130 mA at 5 V DC Power Dissipation: Ranges from 0.4 W (minimum) to 2.7 W (maximum) Thermal Dissipation: Between 1.4 BTU/hr and 9.2 BTU/hr Operating Temperature: 0°C to 60°C (32°F to 140°F) Electrical Specifications The 1771-IGD module supports both positive and negative logic configurations: Positive Logic: ON state: 2.0 to 5.25 V DC OFF state: -0.2 to 0.8 V DC Negative Logic: ON state: -0.2 to 0.8 V DC OFF state: 2.0 to 5.25 V DC These configurations allow for flexible integration with various TTL devices, accommodating different signal logic requirements. Compatibility and Installation The 1771-IGD module is compatible with the following chassis: 1771-A1B 1771-A2B 1771-A3B 1771-A3B1 1771-A4B 1771-AM1 1771-AM2 For proper installation, the module requires the 1771-WH wiring arm, which facilitates secure and efficient wiring connections. The recommended wire size is 14 AWG stranded copper wire with insulation rated for 60°C and a maximum insulation thickness of 1.2 mm. Indicators and Diagnostics The front panel of the 1771-IGD module features LED indicators to assist with diagnostics: One green “ACTIVE” LED indicating the module is powered and operational One green “LOGIC” LED showing the selected logic configuration Sixteen red LEDs corresponding to each input channel, displaying the ON/OFF status of individual inputs These indicators provide real-time status updates, aiding in troubleshooting and system monitoring. Applications The 1771-IGD module is ideal for applications requiring the monitoring of low-voltage digital signals, such as interfacing with TTL-level sensors, switches, and other field devices. Its rapid response time and configurable logic levels make it suitable for diverse industrial automation tasks. By integrating the Allen-Bradley 1771-IGD TTL Input Module into your PLC-5 system, you can achieve reliable and efficient processing of TTL input signals, enhancing the overall performance and responsiveness of your automation setup.