The Allen-Bradley 1771-IR is a six-channel Resistance Temperature Detector (RTD) input module designed for integration with PLC-5 and 1771 Series I/O systems. It facilitates precise temperature measurements by converting analog signals from RTDs into digital data for processing within the PLC framework. Key Features Six RTD Input Channels: Accommodates up to six three-wire RTD inputs, enabling simultaneous monitoring of multiple temperature points. Wide Sensor Compatibility: Supports 100-ohm platinum and 10-ohm copper RTDs, as well as other sensors reporting in ohms. High Resolution and Accuracy: Offers a resolution of 0.1°C (0.1°F) for platinum sensors and 0.3°C (0.5°F) for copper sensors, ensuring precise temperature readings. Rapid Channel Update: Achieves a channel update time of 50 milliseconds for all six channels, facilitating timely data acquisition. Integrated Sensor Excitation: Provides a constant 1mA current for sensor excitation, eliminating the need for external power supplies. Robust Input Isolation: Features 1000V peak isolation between channels and between each channel and the backplane, enhancing system safety and reliability. Comprehensive Fault Detection: Includes open RTD detection with a response time of less than 0.5 seconds, aiding in prompt identification of sensor issues. Technical Specifications Temperature Measurement Range: Platinum RTDs: -200 to +870°C (-328 to 1598°F) Copper RTDs: -200 to +260°C (-328 to +500°F) Resistance Measurement Range: 1.00 to 600.00 ohms Data Formats: Natural binary, BCD actual temperature, or ohm readings Sensor Excitation: 1mA constant current source supplied by the module Input Isolation: Dielectric Test: 1000V peak channel-to-channel and channel-to-backplane for 1 second Common Mode Rejection: 120 dB at 60 Hz up to 1000V peak Common Mode Impedance: Greater than 10 megohms Normal Mode Rejection: 60 dB at 60 Hz Input Overvoltage Protection: 120V rms continuous Open RTD Response Time: Open excitation (terminal A) to overrange: <0.5 sec Open common (terminal C) to underrange: <0.5 sec Open sense (terminal B): drift high Scan Time (all 6 channels): 50 ms Environmental Conditions: Operating Temperature: 0 to 60°C (32 to 140°F) Rate of Change: Ambient changes greater than 1.0°C/minute may temporarily degrade performance during periods of change. Storage Temperature: -40 to 85°C (-40 to 185°F) Relative Humidity: 5 to 95% non-condensing Backplane Power Consumption: 4.25W maximum, 0.85A at 5V Keying: Between 10 and 12 Between 28 and 30 Field Wiring Arm: Cat. No. 1771-WF Dimensions and Weight Product Dimensions: 30.48 x 20.32 x 10.16 cm (12 x 8 x 4 inches) Product Weight: 454 grams (1 pound) The Allen-Bradley 1771-IR RTD Input Module is engineered to deliver accurate and reliable temperature measurements, making it an essential component for industrial automation systems requiring precise thermal monitoring and control.