Hi, Am Sonntag 10 Juni 2007 schrieb Jon Elson: > lines. It is not clear from your description whether the 3 axes > of the smc800 are on separate pins, or all multiplexed through > the same pair of pins. If multiplexed, then only 4 pins are There are two select bits for the motor. The six remaining data bits are then shared between the motors. The two coils of each motor can be driven independently with 0, 20, 60 or 100% current in any direction. This imho is all that's needed for proper microstepping.
The example applications cycle each coil through 0/60/100/60/0/-60/-100/-60 with an offset of 90 degrees when doing "full power". This makes sense, doesn't it? > change the behavior of the stepper driver to do this. But, > having to multiplex the step signals could substantially slow > the available step rate. As long as timing of the smc800 allows to update all three motors within one cycle of the realtime system i don't see a speed problem here. I have taken a look at the schematic and i am quite confident that it should be possible to update all three motors within a very short time frame. > I don't like steppers for positioning applications with greatly > varying loads and speeds, but if you want to go with steppers, > you really want microstepping. As a beginner i don't want spend that much money and i think steppers have a good price/performance ratio, don't they? Till ------------------------------------------------------------------------- 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
