The High-speed counter unit in the FPZ series is equipped with 4 channels and an insulation photocoupler. It has a rated input voltage range of 12-24 VDC for individual input and 3.5-5 VDC for 2-phase, 4-multiple input. This counter unit supports both linear counter and ring counter modes. The counter input type can handle frequencies up to 4 MHz for individual input and up to 16 MHz for 2-phase, 4-multiple input.