This product is a multifunction speed measuring and counting meter with speed measurement, counting, and upper limit alarm output functions. Key features and benefits Functions: provides accurate speed measurement, counting, and an upper limit alarm output to protect equipment and optimize processes. Reliability and simplicity: designed for reliable performance with easy installation and a wide application range. Broad compatibility: supports Hall switch, metal proximity switch, infrared proximity switch, and other detection switch signals. Alarm output: outputs one channel of NPN alarm signal. Practical applicability: suitable for various mechanical equipment and environments where rotational speed measurement and production counting are required. Applications and scenarios Harvesters and agricultural machinery: monitor rotor speed and production counts, with an upperlimit alarm to prevent overspeed and coordinate harvest operations. Machine tools and motors: track RPM and production counts; use the alarm output to trigger warnings when limits are reached. Fans and rotating equipment: monitor speed and counts to safeguard equipment, with the NPN alarm signal interfacing to control systems for timely warnings.