I've gotten a bit farther but now I've run into a hitch I think. I have my component taking in (via hal), Xpos-cmd and Ypos-cmd and providing a direction output (in degrees). I've gotten an angular axis configured as 'A' and it shows up in AXIS and seems to track correctly. However I had to set the following error for the angular axis (MIN_FERROR) ridiculously high to get it to run without giving a 'joint 3 following error', and it still gets one after the blade wraps enough times. I suspect it's because stepgen.x.position-fb is going back to axis.x.motor-pos-fb and axis is complaining because it wasn't the one that commanded the angular axis in the first place, so it thinks the feed back position is wrong. I'm feeding my output (from my component) directly to stepgen.3.position-cmd ( instead of axis.3.motor-pos-cmd feeding it like the other axis's do)
Does this make sense? any ideas? It seems like I should be feeding my angular commanded position somewhere else, but where? thanks Steve Steve Andrusz wrote: > Ahh, I think I'm starting to see the light. Thanks. > > To paraphrase: If the new commanded angle is 'greater than' the > current angle it will rotate clockwise to get there, and if it's 'less > than' the current angle it will rotate ccw to get there. Is that right? > > Thus, if current is 359 and new is 361 it rotates cw. Then, if the next > angle is 359 again, you just command 359 and, since it is 'less than' > the current angle of 361 it will rotate ccw two degrees. > > It make sense now... I hope it's correct. > > Steve > > > > > > Jeff Epler wrote: > >> That ambiguity -- what happens when you go from 359 degrees to 1 degree >> -- is why my code keeps track of "turns". You can get the same blade >> angle by commanding 0 degrees, 360 degrees, 720 degrees, and so on (same >> for -360). But if you change the command from 359 to 1, it will move >> 358 degrees counterclockwise. If you want to move to an angle that is >> in the same direction as 1 degree, but only move 2 degreees, then you >> have to command 361. >> ------------------------------------------------------------------------- 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
