Jon Elson wrote: >Stuart Stevenson wrote: > > >>Gentlemen, >> I have uploaded a picture to imagebin. The name of the picture is stustev. >> This is a screen shot of the feedback from the homing cycle of my >>machine. I am using ppmc boards and EMC2-head. >> The machine moves positive to the home switch. >> I have the latch velocity set very low. >> The machine reverses direction. >> The machine display sets to zero and counts very slow. >> The machine will stop momentarily. >> The display will set to a number that seems to be the disance to >>the start up position. >> The machine then moves to the start up position. (display zero) >> The display turns green. >> Take a look at the screen shot. >> >> >Could anybody take a look at his picture and see if they can >suggest what is happening here? Here's the URL: >http://imagebin.org/8621 > > Well, it clearly appears that index-enable is being reset without any index pulse apparent. I note that there is a base thread that runs faster than the scope sampling thread - where is the ppmc read being done? It's also not completely clear what stage of homing this is (I'm assuming it's the "searching for index" stage).
>Clearly, index-enable is getting shut off before the index pulse >comes true. I cannot see how the hardware or driver, as it is >now written, can do this. > > Me either. There's only one place in the driver where index-enable gets set low, and it's inside the check for index-flag!=0. As for the ini files and such, can you zip them up and stick them on the wiki? I'd like to see all the hal files. [snipped a lot of the ini file] >[TRAJ] > >AXES = 3 ># COORDINATES = X Y Z R P W >COORDINATES = X Y Z >HOME = 0 0 0 >LINEAR_UNITS = inch > > ok - looks like inches here >ANGULAR_UNITS = degree >CYCLE_TIME = 0.010 >DEFAULT_VELOCITY = 0.15 >MAX_VELOCITY = 2.0 >DEFAULT_ACCELERATION = 2.0 >MAX_ACCELERATION = 20.0 > ># Axes sections >--------------------------------------------------------------- > ># Scaling: The OUTPUT_SCALE should be the speed ># in UNITS/second (inches/sec or mm/sec) that would be ># reached if the PWM duty cycle was 100%. It depends on > ># the power supply voltage, motor RPM/Volt factor, and ># gearing/screw pitch. For example: ># ># Power supply voltage 50V ># Motor RPM/V 1000RPM/24V ># Gearing: 2 motor revs per 1 screw rev ># Screw pitch: 0.2" per turn ># ># Max motor speed = 50V * 1000RPM/24V = 2083 RPM ># Max screw speed = 2083RPM * 1(screw)/2(motor) = 1041RPM ># Max table speed = 1041RPM * 0.2"/turn = 208 in/min ># Max table speed = 208 in/min / 60 seconds = 3.47 inches/sec ># ># Since max speed is reached at 100% duty cycle, OUTPUT_SCALE ># should be 3.47 > > Still looks like inches here ># First axis >[AXIS_0] > >TYPE = LINEAR >HOME = 0.000 >MAX_VELOCITY = 2.0 >MAX_ACCELERATION = 6.0 >UNITS = 1.0 >PID_MAX_VEL = 4 > > This looks like inches (IPS) to me as well >BACKLASH = 0.000 >INPUT_SCALE = 10000 >OUTPUT_SCALE = -1.0 > > Dunno why the sign is different here, but I'll assume the motors go in the right direction ... >MIN_LIMIT = -20.0 >MAX_LIMIT = 20.0 >FERROR = 10.0 > > This appears to be mm, or very very wide tolerance for testing purposes >[snip] > ># Second axis >[AXIS_1] > >TYPE = LINEAR >HOME = 0.000 >MAX_VELOCITY = 2.0 >MAX_ACCELERATION = 6.0 >UNITS = -1.0 > > Does anyone know what happens if you have negative units? [snip] ># connect index pulses to motion controller ># do these when index pulsing is figured out >net Xindex axis.0.index-enable ppmc.0.encoder.00.index-enable >net Xindex axis.1.index-enable ppmc.0.encoder.01.index-enable >net Xindex axis.2.index-enable ppmc.0.encoder.02.index-enable > > It would probably be helpful to name these Xindex, Yindex, and Zindex ... [snip] I can't really do any hardware testing because I don't have rev 2 firmware here. Hope this helps - Steve ------------------------------------------------------------------------- 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
