On Jan 4, 2007, at 10:21 AM, [EMAIL PROTECTED] wrote: > "James Reed" <[EMAIL PROTECTED]> wrote: > >> I try to be an open minded person. SInce I don't understand pyVCP >> yet, and >> I know a little about Qt3, I thought trying both would be a good >> learning >> experience. I haven't heard much about what the 2 minutes with >> pyVCP would >> entail, either. I think I have soemwhat of a grasp on HAL, but >> that is >> because of the good documentation EMC has provided. > > Both approaches have their own strong points. As Jeff > demonstrated, the > Qt code can easily make a nice DRO style display when EMC is running. > http://axis.unpy.net/01167918097 > > But it does require EMC to be running - it uses NML to get its > data, and > the NML data comes from EMC. That in turn means that a number of EMC > specific requirements need to be met. For example, if you are > trying to > make a DRO for a manual machine, EMC will trip on a following error as > soon as you turn the crank.
Naw!! Lie to the machine ... set following errors very high. Not nice but workable. Software designed to be a DRO is lots cleaner. Too bad the Mauch/ Kaluga boards have disappeared. Dave > > If you want a plain DRO for a manual machine, you'll either need to do > some programming to make the Qt stuff work without EMC, or you can use > the HAL+PyVCP approach. > > The simplest HAL+PyVCP approach is simply to route the position > from the > encoders to PyVCP "number" widgets for display. However, that > gives you > the raw position. Wherever the axis was when you powered up will > be zero, > and you can't change that. > > A nicer DRO has a "zero" button (either one for each axis, or one that > controls all three axes). When you push it, the display is zeroed and > all subsequent measurements are made from that point. That is > quite easy > to do in HAL. Use a sample/hold block to capture the present > position, > and subtract the captured position from the live position for display. > HAL doesn't have a sample/hold block (yet), but the mux2 block works > as a sample/hold if you feed its output back to one of its inputs. > > I've attached a pair of files, pyvcp-dro.xml and pyvcp-dro.hal, which > (should) implement a 3 axis DRO with one "zero" button for each axis. > I say "should" because I'm away from my Linux box and can't test it. > > To use, you need CVS HEAD (that's the only version with PyVCP at the > moment). Put the attached files in the top level directory of the > checkout, open a shell, and run: > > scripts/halrun -I pyvcp-dro.hal > > To quit, type "exit" at the halcmd prompt. > > Regards, > > John Kasunich > > > > > > > <pyvcp-dro.hal> > <pyvcp-dro.xml> > ---------------------------------------------------------------------- > --- > 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 ------------------------------------------------------------------------- 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
