The external pulse signal (AB phase) can be converted into frequency commands with the following steps: The C200 series only supports open-collector type signals and the maximum speed is 33kHz. When the AB phase pulse signal is connected to MI7 and MI8 for frequency command settings, if the difference between phase A and phase B exceeds 90 degrees, then it is counted as 1 pulse. The pulse counting is stored at D1056 D1054 Present MI8 count value (L word) RO D1055 Present MI8 count value (H word) RO D1056 MI8 corresponding frequency RO D1057 MI8 speed ratio RW D1058 MI8 mapping frequency update speed (ms) RW D1059 MI8 mapping frequency decimal place RW -Then set MI1038 to 1 D1058 Starts MI8 counting RW D1059 Reset MI8 count value RW -For the last step, the internal PLC programming function FREQ will send a frequency command to the drive. -The C200 series doesn’t support the external connection of a PG card. Once MI7 and MI8 are used to receive external pulse signals for frequency commands, the drive will not be able to support closed-loop control mode.