Greetings,

I have a K-Step with closed loop feedback. I am trying to write a program that will home an axis by running it into a hard stop, and using encoder error to tell me I have hit the stop and then zero the axis. 

I am struggling to find the function that tells me what the current error is on a particular axis. Here is what I am trying:

ch0->MaxFollowingError=500; //Set a high following error value

Jog(0,1000); //Slowly jog axis towards limit

while(FollowingError < 10); //Jog until following error

Jog(0,0); // stop

while (!CheckDone(0)) ; // loop until motion completes 

DisableAxis(0); // disable the axis

Zero(0); // Zero the position

EnableAxis(0); // re-enable the ServoTick

ch0->MaxFollowingError=50; // Set normal error limit

Is there a function like "FollowingError(CH(0))" in "KMotionDef.h"? I would really appreciate any help on this, probably a simple thing I am missing.

Thanks,

Scott

As Moray said subtracting should work.  But there is also is a Axis variable ch->LastFollowingError that should also work.

Regards

TK

 

Scott,

To get the following error, read the actual (chX->Position) and commanded (chZ->Dest) channel positions, and do a bit subtraction.

I do notice there is a DestOffset value, but I'm not sure what it does?

However, when following error is exceeded, the axis is automatically disabled.

Moray

On Mon, Oct 10, 2016 at 9:17 PM, cnc_machines@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:

 

Greetings,

I have a K-Step with closed loop feedback. I am trying to write a program that will home an axis by running it into a hard stop, and using encoder error to tell me I have hit the stop and then zero the axis. 

I am struggling to find the function that tells me what the current error is on a particular axis. Here is what I am trying:

ch0->MaxFollowingError=500; //Set a high following error value

Jog(0,1000); //Slowly jog axis towards limit

while(FollowingError < 10); //Jog until following error

Jog(0,0); // stop

while (!CheckDone(0)) ; // loop until motion completes 

DisableAxis(0); // disable the axis

Zero(0); // Zero the position

EnableAxis(0); // re-enable the ServoTick

ch0->MaxFollowingError=50; // Set normal error limit

Is there a function like "FollowingError(CH(0))" in "KMotionDef.h"? I would really appreciate any help on this, probably a simple thing I am missing.

Thanks,

Scott