Bugs item #2478266, was opened at 2008-12-30 21:58 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=106744&aid=2478266&group_id=6744
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: EMC2 Motion Controller Group: None Status: Open Resolution: None Priority: 1 Private: No Submitted By: Jeff Epler (jepler) Assigned to: John Kasunich (jmkasunich) Summary: odd xxx_PERIOD configuration gives funny velocity Initial Comment: A funny configuration, in which SERVO_PERIOD is not a multiple of BASE_PERIOD, causes the emc motion controller to move at the wrong rate (but display the right rate in the AXIS DRO) 1. In axis_mm.ini, change -BASE_PERIOD = 1000000 +BASE_PERIOD = 150000 2. Run emc; F1 F2 ctrl-HOME 3. Open this gcode program: G0 X0 Y0 Z0 G4P1 G1 X100 F[5*60] G4P1 G0X0Y0Z0 M2 4. Open a halmeter on the signal Xvel 5. Run the program Expected behavior: during the G1 move, Xvel is close to or exactly 5 Actual behavior: Xvel is approximately 4.7 This problem exists because motion makes certain calculations based on the inifile SERVO_PERIOD and TRAJ_PERIOD, not the actual period of the HAL threads. Normally, when the inifile values are exact multiples of each other and/or BASE_PERIOD is small, this effect is small. However, in some cases the effect can be severe. The original report was of a difference of 20%, though nobody else has exactly recreated it. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=106744&aid=2478266&group_id=6744 ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
