The Allen-Bradley 1771-WN is a high-speed counter module designed for the PLC-5 family of programmable logic controllers. This module is engineered to accurately process fast pulse trains from devices such as encoders, flow meters, and proximity sensors. It provides two independent counting channels, making it ideal for applications requiring precise position tracking, velocity measurement, and totalizing. The 1771-WN enhances the capabilities of the PLC-5 system by offloading high-speed counting tasks from the main processor, ensuring reliable and real-time performance in demanding industrial automation environments.