Allen-Bradley 1771-IL Isolated Analog Input Module

The Allen-Bradley 1771-IL Isolated Analog Input Module is an 8-channel analog input card designed for PLC-5 systems. It plugs into a 1771 I/O chassis and provides galvanic isolation for each input channel, with an isolation rating up to 1000 V. The module accepts analog signals from sensors in either current or voltage form, converting them to digital data that the PLC-5 processor can read while keeping the input circuitry isolated from the controller and from each other to improve noise immunity in demanding environments. As part of the 1771 I/O family, the 1771-IL is used to monitor process variables such as temperature, pressure, level, and other sensor signals that originate in industrial plants, then feed this information into ladder logic or structured control routines. The eight inputs support configuration for per-channel signaling and are designed for compatibility with legacy Allen-Bradley PLC-5 automation architectures, delivering reliable data collection from remote or noisy installations where isolation is critical.