On Apr 1, 2009, at 7:34 PM, Kirk Wallace wrote: > On Wed, 2009-04-01 at 18:43 -0700, Dave Engvall wrote: >> <snip is all and start over> >> >> Am back from the beach and have tried things again. >> >> Finally found a fundamental mistake. 1525BR amps expect a >> differential input; so battery boxes give the expected result. >> However, the dacs are ground referenced. After I finally caught on I >> wired the 1525 inputs with gnd to gnd and + dac to -amp input. >> Now things move. >> >> The only problem is that both axes move in the wrong direction. So: >> how do I cleanly reverse the movement without having to >> fool with the encoders? >> >> BTW-the X axis that has absolutely awful response like 200 ms to max >> velocity tuned to about 0.001 at 60 ips and 0.00004" at 10 ipm. >> We'll see what we can get out of the Y axis. ;-) >> >> So the m5i20 does really run right out of the box. The same cannot >> be said of my aging brain. >> >> Dave > > I'm glad your making progress. It has been a while since I have had to > think about this, but I believe you can change the direction of an > axis > by changing the .ini file OUTPUT_SCALE = 1 for the axis, to > OUTPUT_SCALE > = -1. If you have encoders, the .hal encoder settings may need to be > adjusted too.
> Also I would have connected your amp inputs DAC signal > ground to - input and DAC signal to + input, but I haven't studied > your > particular setup. Indeed that ( + and - ) would be the intuitive way to do it but it doesn't work. I tried changing the sign on INPUT SCALE and the sign on OUTPUT_SCALE independently but that doesn't work either. Axis moves on command and then faults on following error. So I have more work to do. Dave > --------------- > Kirk > http://www.wallacecompany.com/machine_shop/ > > > > ---------------------------------------------------------------------- > -------- > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
