Mitsubishi Electric PLC Control Units, Counter, High Speed, MELSEC-F Series, Type: Counter, Channel number(ch): 2, Count Input Format: Open collector, differential line driver, Maximum Response Frequency (1 Phase, 1 Input): 200 kHz or less, Maximum Response Frequency (1 Phase, 2 Input): 200 kHz or less, Maximum Response Frequency (2 Phase Input): 50 kHz or less (multiplication by 4) / 100 kHz or less (multiplication by 2) / 200 kHz or less (multiplication by 1)