Quote Originally Posted by A_Camera View Post
I don't know the DM856 or the Cwd556, but if you are using CSMIO then I think one problem can be the pulsing frequency. If I am not wrong, CSMIO is capable of running much faster than 200kHz and most drivers can only handle maximum 200kHz pulsing. Perhaps that was not an issue with the DM856, but may be an issue with the Cwd556. I know I can run my DQ542MA at 400kHz, even though they are also only for 200kHz, but since I occasionally experienced some issues when I ran them outside the specs, I reduced back to 200kHz and my problems were gone. So, have a look at your pulsing frequency and reduce to 200kHz if set higher. Also check the specs of Cwd556 regarding this, and keep your pulsing at or below that level.
Although it is capable of high pulse rates, there isn't any control on the CSMIO to limit max pulse speed. However, this doesn't matter. Pulse rate is decided by how fast the motor turns, and how many steps per rev. So, 5000mm/min axis with 5mm lead ballscrew means motor turns at 1000RPM (assuming direct or 1:1 belt drive). 200 steps per rev with 8x microstep setting (pretty typical) gives 3200 microsteps/rev, that is 3200 pulses/rev. So, that's 320000 pulses/min, roughly 5300 pulses/sec. Well within the capabilities of any of the usual drivers. It is possible for pulse rates and wait time between dir and step pulses to be a problem in some systems (e.g. where you can change pulse length) but these are fixed in the CSMIO firmware and seem to work well. I can't think of an obvious reason why you would want to pulse a stepper much faster than this; usually the reason for needing faster hardware is to cope with encoder pulse output from servo systems rather than open-loop steppers.