PWM Settings

[Gunar]

if you add a 10uF capacitor I 'd connect the output terminal to 2 diodes to prevent the output being taken below the ground or above +10V supply terminals John

Sorry for the mistake on my previous post John. I have these capacitors
0.47uF 400v, 100uF 25v, 0.047uF 100v. Would any of these be suitable?

[Gunar]

I also found these
10mF 50VMP, IEC NP 4.7MFD 50V, IEC NP 16MFD 50V

[Neale]

No, the Gecko output is already filtered so you do not need capacitors of any value. Looks like the output voltage of the Gecko is about right anyway for the speeds demanded so looks more like a VFD issue. My HY VFD works fine with reasonable linearity so maybe there are some other parameters that can affect this?

[Gunar]

Thanks Neale, I will check my VFD parameters again

Nicolas

[Gunar]

Hey Neale, if you have Mach3 with your VFD can you tell me what parameters you have on the Motor Tuning page for the spindle? I have: Stepsper=1, Velocity=120, Accel=4, Steppulse=2. Dirpulse=2. Some say these settings have no effect on PWM and some say the same but suggesting the Accel/Velocity should be about in the middle of the scale for each

[Neale]

As I understand it, the g540 is basically just a breakout board and four stepper drivers in a single box. Mach3 does all the real work. I am using a CS Labs CSMIO-IP/M where a lot of the processing is off-loaded from Mach3 to the motion controller. Things like spindle control are also handled partly by Mach3 and part by the IP/M which has its own configuration parameters so I'm not sure that any of my system's settings would be relevant and might be misleading. All I can say is that the IP/M and the HY inverter do seem to play well together but I did have to follow the various manuals very carefully to get it all set up. The only thing I forgot to do was change the motor pole parameter in the VFD as the front panel display currently reads half the demanded speed but that's a trivial problem. In your case, there is a non-linearity between input voltage to VFD and VFD speed/frequency which is more puzzling.

[Gunar]

Thanks for your time Neale, much appreciated