I eventually managed to merge a few hal files and ini files to Change the stepgens etc to work in velocity mode. I have just connected up to the machine,and initial testing is excellent. Strange thing though ,i have not entered any deadband figures yet but the crackling seems to have gone. I will let you know how more in depth testing works out, but for now all is good. Can anyone tell me what the maximum figure is that i can set in the beaglebone for stepgen max velocity? At the moment my stepgen max velocity is 42 And the Max velocity is 35 At 1000 steps per mm I seem to remember it max's out at 45khz?
On 24/02/14 17:22, Jeff wrote: > Hi, > > I'm *guessing* that they are the older Geckos (non digital). The older > drives had to have the DIR line stable for quite a time after the STEP pulse. > I believe this was to manage the resonance compensation circuit. This makes > me think the DIR line was not actually latched at the time of the STEP pulse. > If this is the case, the external DIR line would play an active role in the > direction the current is going to be going in the motor windings. Thus, at > the start of each PWM cycle (about 20KHz) the DIR line would determine which > direction the current should go (even in a stationary motor). As the DIR > line changes, the standby current in the motor will be reversed. The rate of > DIR reversal coupled with the 20KHz ends up giving a beat frequency in the > audible range. Another guess would be that the actual noise "signature" > would be where the drive stopped within the 10 microstep range. You could > end up having 10 different crackling noise characteristics depending on which > mic rostep you stopped at. > > While the noise might be annoying, I don't think (another guess) it would > cause a problem for the drive as long as the correct DIR polarity is stable > before the next STEP pulse comes in. > > Jeff > > ---------------------------------------- >> Date: Sat, 22 Feb 2014 11:30:59 -0800 >> From: p...@mesanet.com >> To: emc-users@lists.sourceforge.net >> Subject: Re: [Emc-users] Crackling motors using Beaglebone >> >> On Sat, 22 Feb 2014, Mark Tucker wrote: >> >>> Date: Sat, 22 Feb 2014 19:20:57 +0000 >>> From: Mark Tucker <m...@rmtucker.f2s.com> >>> Reply-To: "Enhanced Machine Controller (EMC)" >>> <emc-users@lists.sourceforge.net> >>> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> >>> Subject: Re: [Emc-users] Crackling motors using Beaglebone >>> >>> John >>> >>> Thank you so much for the insight of how that work and it explains a lot. >>> But as you stated it would be hunting back and forth.Which i assume it >>> would have to pulse the step line? >>> And a number of people have scoped the outputs and only found the Dir >>> line hunting back and forth,i wonder why it is not detected on the step >>> line.? >>> And if it is only the dir line,why would the motors make a noise at all? >> >> The internal stepgen position has a resolution of a small fraction of a step >> (1/10000 of a step in Johns example) so it can hunt back and forth without >> emitting a step. >> >> As to why a step drive pays any attention to the dir signal without a step >> pulse I do not know, seems like a mistake to me. >> >> >> Peter Wallace >> Mesa Electronics >> >> ------------------------------------------------------------------------------ >> Managing the Performance of Cloud-Based Applications >> Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. >> Read the Whitepaper. >> http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > ------------------------------------------------------------------------------ > Flow-based real-time traffic analytics software. Cisco certified tool. > Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer > Customize your own dashboards, set traffic alerts and generate reports. > Network behavioral analysis & security monitoring. All-in-one tool. > http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ Flow-based real-time traffic analytics software. Cisco certified tool. Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer Customize your own dashboards, set traffic alerts and generate reports. Network behavioral analysis & security monitoring. All-in-one tool. http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
