Stuart Stevenson wrote: > Gentlemen, > I don't want to be pushy. I haven't seen any reference to the > homing problem for a few days. Is it still receiving some attention? I > have been working on some other issues. Tomorrow (later today) I will > be working on the machine. If there are some instructions I would like > to try them shortly. The only thing I can think of is to get a Halscope trace of the HAL pins : ppmc.0.encoder.00.position
and ppmc.0.encoder.00.index-enable and possibly also : axis.0.index-enable and see if one of us can figure out what the problem is. John Kasunich seems to think he knows what is wrong, I'm less sure of it, because I can't duplicate it here. His scenario is that the PPMC logic that detects an index pulse has been seen gets triggered, while the logic that resets the encoder count from the index pulse fails to sense it. So, the driver and homing state machine go about their tasks assuming the counter has been zeroed when it has not been set to zero. That DOES sound like the scenario that would cause your observed behavior, however, so John may well be right! The way I designed this, which may be all wrong, is that the "zero encoder on index pulse" has the same noise filtering scheme that filters the A & B encoder signals, while the "have we seen the index pulse" logic doesn't. The obvious fix is to make the detect index pulse logic depend on the same filtering as the zero on index logic. I'd do this in a second if I could reproduce the same problems here. Maybe I should just do this and send you an EPROM on Monday. If you can run the Halscope trace when the problem occurs, and it shows ppmc.0.encoder.00.index-enable turning off while the encoder position continues to count, that would pretty much say John is right. Jon ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/emc-users
