The Bently Nevada 135813-01 is a 3500/25 Keyphasor Module, a crucial component of the 3500 Machinery Protection System. This two-channel module is designed to condition input signals from proximity probes or magnetic pickups to generate a precise once-per-turn or multiple-event-per-turn timing signal, known as a Keyphasor signal. This signal is essential for other monitor modules in the 3500 rack, providing them with accurate speed and phase reference data required for synchronous vibration analysis and overall machinery health diagnostics. Its reliable performance ensures accurate data for critical rotating machinery protection and condition monitoring applications.