--- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@...> wrote:
>
> Hi Erik,
>  
> KFLOP handles motion profiles as double precision floating point equations so there is no need for you to be concerned with clock rates and such.
>  
> In Microstepper mode the units are in sine wave "cycles".  So a movement of 1.00 would generate one full sine wave to the stepper coils.  Most Stepper motors have 50 poles (200 full steps/rev - there are 4 full steps in one full cycle).
>  
> The Step Response Screen has the motion profile parameters the allow you to set the Max Velocity, Max Acceleration, and Max Jerk in units of cycles/second, cycles/second^2,and cycles/second^3 respectively.
>  
> So for example:
>  
> to move two revolutions you would command a move size of 2 x 50 cycles/rev = 100 cycles
>  
> to limit the velocity to 600 RPM (10 revs/sec) you would set the Max Vel to 10 x 50 = 500 cycles/second
>  
> to accelerate up to 500 cycles/second in 0.5 seconds you would need 500 cycles/sec / 0.5 seconds = 1000 cycles/sec^2 (without limit on Jerk)
>  
> to limit the Jerk so that the Acceleration is applied gradually over 0.1 seconds would be a Max Jerk of 1000 cycles/sec^2  /  0.1 seconds = 10,000 cycles/sec^3
>  
> Regards
> TK
>
> From: quelisto <quelisto@...>
> To: DynoMotion@yahoogroups.com
> Sent: Friday, February 3, 2012 1:46 PM
> Subject: [DynoMotion] Re: Various issues
>
>
>  
> Tom:
>
> I now fully understand the current setting, thank you.
>
> What I do not get is how one sets the resolution of the microstepping. This of course would affect the number of microseconds per second needed to get a given rpm. Is there something in a register that can adjust either a clock rate, number of bits of resolution ,etc?
>
> Thanks.
>
> -Erik-
>
> --- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@> wrote:
> >
> > Hi Erik,
> >  
> > Correct.  SnapAmp does microstepping with a stepping motor by applying sinewave currents to the motor with an amplitude set via the StepperAmplitude parameter.  The current is specified as a value 10-bit value (0-1023) which specifies the total SnapAmp current range from 0 to 35A.  So for example a stepper motor requiring 5A would have a StepperAmplitude setting of:
> >  
> >  5A / 35A x 1024 =  146
> >  
> > SnapAmp works differently than most Step/Dir drives.  The microstepping resolution is virtually infinite but then resolution is determined by the possible current levels which is determined by the current amplitude.
> >  
> > You should be able to plot the actual currents on the Step Response Screen.
> >  
> > Hope this answers your questions.
> >  
> > Regards
> > TK  
> >
> > From: quelisto <quelisto@>
> > To: DynoMotion@yahoogroups.com
> > Sent: Friday, February 3, 2012 11:12 AM
> > Subject: [DynoMotion] Various issues
> >
> >
> >  
> > 1) How do you control motor current with the SnapAmp? I am aware there are peak overcurrent alarms that can be set to disable the SnapAmp. However, I am instead looking to control the phase currents via the PWM generator. There is no mention of a resistor or register that I am to program to set this current level.
> >
> > 2) What is the purpose and what are the units of chx->StepperAmplitude? Are these the number of discrete PWM states for microstepping?
> >
> > 3) Does the SnapAmp perform microstepping? I put the following code snippet (below) in the main function. The SnapAmp behaved as though it were performing regular full steps.
> >
> > ch0->InputMode=NO_INPUT_MODE;
> > ch0->OutputMode=MICROSTEP_MODE;
> > ch0->Vel = STEPR_NORMAL_V; // Default velocity
> > ch0->Accel=70;
> > ch0->Jerk=400;
> > ch0->InputChan0=0;
> > ch0->InputChan1=1;
> > ch0->OutputChan0=8; // Stepper
> > ch0->OutputChan1=9;
> > ch0->LimitSwitchOptions=0x0;
> > ch0->InputGain0=1.000000;
> > ch0->InputGain1=1.000000;
> > ch0->InputOffset0=0.000000;
> > ch0->InputOffset1=0.000000;
> > ch0->invDistPerCycle=1.000000;
> > ch0->Lead=0.000000;
> > ch0->MaxFollowingError=1000000000.000000;
> > ch0->StepperAmplitude=250.000000;
> >
>