On Friday 26 April 2013 17:13:24 Andy Howell did opine: > Hello, > > After upgrading from 2.4.6(?) to 2.5.2, I'm getting a following error > on my Z axis. This is a open loop stepper setup. The only way I could > fix this is by setting MIN_FERROR=1. Previously is was 0.01. > > The SCALE for Z is twice that of X and Y. I tried reducing the > MAX_VELOCITY from 2.5 to 1.0, but that didn't seem to help. > > I'm using the Gecko 540 controller. > > I noticed that the sample Gecko_540B3.hal dirHold and dirSetup are much > different from my config: > > setp stepgen.2.position-scale [AXIS_2]SCALE > setp stepgen.2.steplen 1 > setp stepgen.2.stepspace 0 > setp stepgen.2.dirhold 15200 > setp stepgen.2.dirsetup 15200
If this code is actually in effect, I see 3 potential problems. stepspace = 0 s/b an illegal setting, and if the backspace move goes too fast to leave a space, BOOM. Then unless your opto-isolation is done with CDS cells, the dirhold & dirsetup are both quite large unless your don't have the reset timing set in the parport loadrt and setp lines. In that case the reset timing matches the BASE_THREAD period as each state will be one BASE_THREAD in duration. So the above figures don't seem to grok at all well to me. > My .hal has: > > setp stepgen.2.position-scale [AXIS_2]SCALE > setp stepgen.2.steplen 1 > setp stepgen.2.stepspace 1 > setp stepgen.2.dirhold 2 > setp stepgen.2.dirsetup 1 Much more reasonable. IIRC the unit value is in microseconds > > Any idea why the behavior changed with the upgrade? > > I tested the latency again, and that is fine. Its less than 3000. > > [EMCMOT] > EMCMOT = motmod > COMM_TIMEOUT = 1.0 > COMM_WAIT = 0.010 > BASE_PERIOD = 35000 > SERVO_PERIOD = 1000000 > > X and Y axis are configured the same and works fine: > [AXIS_1] > TYPE = LINEAR > HOME = 0.0 > MAX_VELOCITY = 2.5 > MAX_ACCELERATION = 10.0 > STEPGEN_MAXACCEL = 20.0 > SCALE = -10000.0 > FERROR = 0.05 > MIN_FERROR = 0.01 > MIN_LIMIT = -0.1 > MAX_LIMIT = 4.700 > HOME_OFFSET = -0.1 > HOME_SEARCH_VEL = -0.050000 > HOME_LATCH_VEL = -0.025000 > HOME_IGNORE_LIMITS = YES > BACKLASH=0.0115 > > Z Axis - I had to make MIN_FERROR much larger. Changed from 0.01 to 1. > [AXIS_2] > TYPE = LINEAR > HOME = 0.0 > MAX_VELOCITY = 1.0 > MAX_ACCELERATION = 10.0 > STEPGEN_MAXACCEL = 20.0 > SCALE = -20000.0 > FERROR = 0.05 > MIN_FERROR = 1 > MIN_LIMIT = -10.200 > MAX_LIMIT = 0.10 > HOME_OFFSET = 0.1000 > HOME_SEARCH_VEL = 0.050000 > HOME_LATCH_VEL = 0.025000 > HOME_IGNORE_LIMITS = YES > BACKLASH=0.0005 You have a ball screw in Z only? My acme screw BACKLASH with twin nuts to adjust backlash is more like .005" with a bit of wear, .0035" at best. > I set this up long ago, so I'm likely forgetting something :( So am I :) > Thanks, > > Andy > > ------------------------------------------------------------------------ > ------ Try New Relic Now & We'll Send You this Cool Shirt > New Relic is the only SaaS-based application performance monitoring > service that delivers powerful full stack analytics. Optimize and > monitor your browser, app, & servers with just a few lines of code. Try > New Relic and get this awesome Nerd Life shirt! > http://p.sf.net/sfu/newrelic_d2d_apr > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> Always think of something new; this helps you forget your last rotten idea. -- Seth Frankel A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
