Allen-Bradley 57C421

The 57C421B Reliance Pulse Tach Input Module, part of the Automax series by Reliance Electric, is engineered for pulse tach input applications, ensuring reliable performance in various automation settings. This module features a single input channel and supports differential, emitter-follower, open-collector, or single-ended input types, operating at voltage levels from TTL to a maximum of 13.2V DC. With a minimum input current of 5mA and a rated input current of 10mA at 4.0V DC, it offers robust functionality along with a remarkable isolation rating of 2500V AC (rms). The module is designed to accommodate long-distance connections with a maximum wire length of 600 feet (180 meters) and boasts a combined digital and analog filter with a cut-off frequency of 250 kHz, making it versatile for complex applications. For comprehensive guidance on setup, operation, and troubleshooting, users can refer to the detailed user manual, J-3680.