The Allen-Bradley 1771-IYC is a sophisticated PLC-5 thermocouple input expander module that enhances analog input capabilities within a 1771 I/O chassis. It features 8 floating differential inputs compatible with thermocouple types B, E, J, K, T, R, and S. The module supports block transfer programming for input and configuration data without needing an external power supply. It draws 750mA at 5V from the backplane and offers a 25ms channel update time. Additional features include user-selectable temperature alarms, open circuit detection, and self-diagnostics, operating reliably within a 0 to 55 °C range.