On Monday 28 March 2016 16:18:18 jeshua wrote: > > On Mar 26, 2016, at 7:13 AM, Gene Heskett <[email protected]> wrote: > > > > I am not fam with that driver Jeshua, but most of these drivers > > have 3 inputs, step, dir, and enable. I suspect the enable might not > > be wired correctly. In my setups, using the 2m542 driver, IIRC > > leaving the enables unconnected actually enables them. Or you can > > use a pin on the BoB to drive all 3 of them if the BoB's output has > > enough current sinking ability to drive all the axis's drivers, and > > you actually have a spare pin on the BoB. > > > > I just checked the .hal file for my G0704, and the only place I am > > sending the motion modules axis#-enable signals is to the pid's & > > stepgen's in the 5i25, so I either do not have the driver enables > > wired to the BoB, or they are wired permanently in the on state. > > Probably the latter, and I can get a ladder (that box is on a high > > shelf to miss most of the swarf but the lid is off, when I find my > > round tuit, I'll modify a drill pattern and put an exhaust fan on > > the lid) and check because I know all the + terminals are hard wired > > to a 5 volt bus, but do not, nearly 2 years later, remember if I > > just grounded the - terminals, or they are tied someplace active. > > > > But that is something to check, the 6550 may have to be wired "on" > > at its enable input. I do not have manual wheels on any axis, so no > > reason to disable the drivers to make them easier to turn exists. > > > > This may not be the problem, but its also something that might trip > > up a builder. I hope it helps. > > Hi Gene, > > Thanks for all the suggestions everyone. > > Hmm, I think the one thing I do have wired up correctly is the > enabled. > > Because as it is the motor is off until I press the “Test Axis” button > in the stepper wizard, then immediately holds its position under power > (and makes a high pitch whine). If I unplug the enable, or close the > Test Axis dialog, the motor goes dead. Why we are not getting the 2nd > LED lit I have no idea.
This makes me ask if perchance, you are feeding the step signal to the dir and vice versa? In that event toggling the dir will probably make it step back and forth whatever small fraction of a step the microstepping switches are set to, and that could make a 1 khz tone w/o moving the motor more than a couple arc-minutes. Thats the sort of thing I'd trot out an o-scope to look at just to confirm I screwed up ( don't ask me how I know ). Since you might not understand what you are looking at on the scopes screen, I won't push that, other then to have you check, from the generated .hal file, all the way thru to the drivers inputs, that the signals haven't crossed each other. There are several places that could happen, including the .hal file itself. > > I still am not sure why the driver has Pulse + / - and Dir + / -. I am > accustomed to only a single pulse and dir. > They are opto-coupled, and both ends of the opto device must be connected to the world inhabited by the BOB and its power supply. And because the BOBs usually have a TTL output, they can pull 10x the current to ground that they can pull up to the 5 volt rail, so normally we feed the 5 volts to the + terminals, and the control signal from the BOB goes to the - terminal of that input. This give at least a 1500 volt barrier that only the light from the optocoupler can cross, preventing voltage spikes from destroying either the BOB, or the rest of the input circuitry in the driver. One caveat: Crossing that barrier can and will screw up the linearity of controlling a PWM controlled motor, so I've been forced to extract the opto's in the BOB before I could control the spindle motor at all well. They tend of have a much shorter turn on than turn off time. > If I understand correctly, I just tried connecting the signals from > the controller to the - pins and the +5v from the enable to the plus > pins, but no luck. With the drive inactive, meter that 5 volt line making sure its within .2 volts of 5 volts. Then read the - pins, which s/b effectively open circuited, and reading something in the 3.5 to 4.2 volts, dropping to a few tens of millivolts if you send it a signal to run at the high speed limit, say a 99% ON PWM signal, and since the logic is upside down, you will read a pretty low volage. > Since I have wired this up based this a photograph (from someone that > has it running with LinuxCNC in a video), can anyone point me to a > diagram for a similar setup? Guess we will try contacting the author, > see if he responds. In the picture shown, it looks like he is only > using the Dir + and Pulse +, I don’t see any leads to the - pins. > > http://www.technoshamanarchist.net/wp-content/uploads/electronics_2.jp >g Neither do I, but the pix was taken at the perfect angle to hide that. :) > Best, > > Jeshua Lacock > Founder/Engineer > <3DTOPO.com> > GlassPrinted.com > > > ---------------------------------------------------------------------- >-------- Transform Data into Opportunity. > Accelerate data analysis in your applications with > Intel Data Analytics Acceleration Library. > Click to learn more. > http://pubads.g.doubleclick.net/gampad/clk?id=278785471&iu=/4140 > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785471&iu=/4140 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
