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General Mach Discussion / Mach 3 constant pulse width or constant duty cycle?
« on: May 23, 2015, 11:11:52 AM »
Hello everybody,
I was wondering if Mach 3 has a constant pulse width for the step output pulses with varying frequency or a constant duty cycle with varying frequency for different speeds? I am having trouble with a (Chinese) USB Mach 3 controller that puts out constant duty cycle with varying frequency that upsets my stepper drivers. I checked the output on the scope and the duty cycle is always around 50%, at low frequencies from 300 Hz all the way up to 15 kHz. Pulse width is not stable also. Steppers don't run smooth and sometimes hesitate or run rough. Positioning is correct though.
Direct to Mach 3 through parallel port and BOB all is OK so I was wondering if this could be the culprit. Anybody has some screendumps from a scope showing the pulse train at different speeds?
Thanks,
G21
I was wondering if Mach 3 has a constant pulse width for the step output pulses with varying frequency or a constant duty cycle with varying frequency for different speeds? I am having trouble with a (Chinese) USB Mach 3 controller that puts out constant duty cycle with varying frequency that upsets my stepper drivers. I checked the output on the scope and the duty cycle is always around 50%, at low frequencies from 300 Hz all the way up to 15 kHz. Pulse width is not stable also. Steppers don't run smooth and sometimes hesitate or run rough. Positioning is correct though.
Direct to Mach 3 through parallel port and BOB all is OK so I was wondering if this could be the culprit. Anybody has some screendumps from a scope showing the pulse train at different speeds?
Thanks,
G21