I've been trying to pin down follow tracking error in that after I run Axis.ngc my dro doesn't agree with the position according to the Axis display. After trying many things as far as acceleration and velocity settings I thought maybe I ought to take a look at what was coming out of emc. Using halscope connected to the parport pins that drive the motor driver I could't believe what I was seeing. As I jogged at maximum velocity hal showed an increasing frequency as the table accelerated, but then the displayed frequency decreased after the acceleration period and then increased again as it entered the deceleration phase, finally decreasing to zero as the table stopped. If the halscope scaling is correct, the max frequency reached was around 400 hz during acceleration and deceleration After the acceleration phase the frequency slowed to zero as the table stopped. The rise and falltimes were 0.5 ms. Yes 500 uS.! Maybe I should mention that I am using the quadrature stepper.
I then looked at the signals with a real scope and didn't see that anomly. As expected, the frequency increased as the table accelerated reaching a maximum of 1 Khz after the acceleration phase and decreased to zero as the table stopped. Rise and fall times were less than 1 uS. So maybe the problem is I don't know how to use halscope or maybe its frequency response is very slow. Can any one educate me on this? Jack Ensor ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
