#emc-devel | Logs for 2009-05-28

[12:49:24] <skunkworks300> Good morning. I might actually be awake today
[12:52:24] <jepler> hi skunkworks300
[12:53:49] <skunkworks300> Did zen make it home better than the start of the fest?
[12:54:41] <jepler> yeah, I think so
[12:54:50] <jepler> the real test will be when I cut a board on it
[12:55:31] <skunkworks300> :)
[17:42:03] <skunkworks300> skunkworks300 is now known as skunkdesk
[17:42:10] <skunkdesk> skunkdesk is now known as skunkworks_
[19:37:23] <alex_joni> hey seb_kuzminsky
[19:37:35] <seb_kuzminsky> hi alex_joni
[19:37:55] <alex_joni> I've only marginally watched the thread in the forum on encoder index & hm2-stepgens
[19:38:31] <alex_joni> are there any plans to replicate the SW stepgen functionality?
[19:38:46] <seb_kuzminsky> hmm
[19:38:49] <alex_joni> that one does reset the position on index
[19:39:08] <seb_kuzminsky> how? i looked at the stepgen manpage but didnt see it
[19:39:17] <seb_kuzminsky> guess i didnt look well enough :-(
[19:39:25] <alex_joni> hmm.. at least that's how I remember it
[19:39:37] <alex_joni> * alex_joni looks
[19:40:23] <seb_kuzminsky> i think there should be a pin called "reset", which zeros position-fb
[19:40:26] <seb_kuzminsky> i think that would do it
[19:41:25] <alex_joni> yes and no
[19:41:36] <alex_joni> it should work if it's homing slow enough
[19:41:45] <alex_joni> if it goes faster it should be done in the fpga
[19:41:51] <alex_joni> (like a regular servo does)
[19:41:59] <alex_joni> not sure how easy that would be :)
[19:43:09] <seb_kuzminsky> even if it did that... i think that gtom's setup is just broken by design
[19:43:19] <seb_kuzminsky> i think there's no attempt to merge the feedback from the stepgen and the encoder
[19:43:30] <seb_kuzminsky> he's just using the encoder position
[19:43:48] <seb_kuzminsky> if there's any drift between the encoder and the stepgen, he's going to be out of sync and his machine's going to misbehave
[19:44:00] <seb_kuzminsky> he should just use velocity mode on his stepgen and pid for position control
[19:44:10] <seb_kuzminsky> that's how i understand it
[19:44:46] <alex_joni> hmm.. I think it should work as he set it up
[19:45:09] <seb_kuzminsky> please feel free to jump into the thread ;-)
[19:48:10] <alex_joni> I probably will at some point, too tired tonight for that though :D
[19:48:15] <seb_kuzminsky> heh
[19:48:31] <alex_joni> loong day ;)
[19:48:44] <seb_kuzminsky> i tried to write down my understanding of his setup and why i think it wont work
[20:11:48] <cradek> homing to index can't work unless the position resets upon index, right?
[20:12:40] <cradek> and I don't see how you'd use two position feedbacks unless you use them as velocity (like seb said)
[20:12:50] <jepler> yes, that's my understanding
[20:13:13] <cradek> I didn't look at his config after he described how extremely strange it is
[20:13:43] <cradek> (also i didn't see a problem report that specifically says what he thinks it's doing wrong)
[20:13:57] <cradek> I could have missed it.
[20:17:35] <seb_kuzminsky> ok good, that's what i thought
[20:56:04] <cradek> * cradek stares blankly at the python arc_feed
[20:59:49] <jepler> cradek: I'm sorry it's so crappy
[21:00:08] <cradek> not your fault
[21:23:14] <Lerman______> Lerman______ is now known as Lerman
[21:23:53] <cradek> hi ken!
[21:24:32] <jepler> Lerman: hi
[21:53:27] <micges> some simple cleanup patch to consider: http://pastebin.ca/1438584
[21:54:24] <micges> jepler: did you saw my patch about duplicate abort code ?
[21:55:51] <jepler> yes, but I didn't apply it because I'm not confident I can see all the consequences of it
[22:07:49] <micges> abort code in emcTaskAbort was once again executed after return from function, after patch only difference is
[22:07:49] <micges> that emcTaskPlanClose() is called before emcTaskQueueCommand(&taskPlanSynchCmd);
[22:08:44] <micges> but sure maybe that not only consequence
[22:10:47] <micges> I've just on way to understanding-> cleaning-> better understanding-> adding run from line to task
[22:10:52] <micges> bbl
[22:11:21] <jepler> I am not the right person to evaluate and apply your patches to task.
[22:11:31] <jepler> I am not sure who is, but I think alex_joni has done more work in that area
[22:14:08] <micges> good night all