On Wed, 28 Nov 2012, Dave wrote: > Date: Wed, 28 Nov 2012 12:34:17 -0500 > From: Dave <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: [email protected] > Subject: Re: [Emc-users] 7i39 and brushless servo > > On 11/28/2012 12:21 PM, Peter C. Wallace wrote: >> On Wed, 28 Nov 2012, Viesturs L?cis wrote: >> >> >>> Date: Wed, 28 Nov 2012 18:49:30 +0200 >>> From: "[UTF-8] Viesturs L?cis"<[email protected]> >>> Reply-To: "Enhanced Machine Controller (EMC)" >>> <[email protected]> >>> To: "Enhanced Machine Controller (EMC)"<[email protected]> >>> Subject: [Emc-users] 7i39 and brushless servo >>> >>> Hello! >>> >>> I am having difficulties getting 7i39 card to drive my servos. >>> Motor datasheet is here: >>> http://www.cutting.lv/fileadmin/user_upload/motor.pdf >>> >>> Motor is attached to first channel (motor 0)of 7i39 card, nothing is >>> connected to the second channel (motor 1). >>> >>> All three jumpers are on the left side. >>> >>> I tried to figure out the Hall pattern and I _think_ it is pattern no: >>> 44 from table in this page: >>> http://linuxcnc.org/docs/html/man/man9/bldc.9.html >>> >>> Datasheet says that motor has 8 poles, and when I tried to turn it by >>> hand, there were 8 positions that shaft tried to stick into, so that >>> might be correct. >>> What is puzzling me is the fact that during one revolution of motor >>> shaft the Hall signals cycle 4 times. Is that correct? >>> >>> I tried to get the motor to spin this way: >>> 1) disconnected encoder.0.position from axis.0.motor-pos-fb >>> 2) disconnected bldc.0.value from pid.0.output >>> 3) issued this command >>> setp bldc.0.value 0.85 >>> >>> Motor did turn, but not really smoothly. But it did turn around >>> instead of simply jerking back and forth. >>> Currently there are CR2 and CR12 leds turned on as soon as I power on >>> machine and CR8 and CR9(?) leds are turned on as soon as I "toggle >>> machine on" with F2. >>> >>> Now I cannot get it to turn. If I turn it by hand, the feeling is that >>> it has no power, but the 7i39 has motor power supplied. I checked. >>> Encoder and Hall sensor signals are received - I can see them in HAL >>> Meter (either bldc.0.hall1, bldc.0.hall2, bldc.0.hall3 or >>> bldc.0.rawcounts are changing) as I turn motor by hand. >>> >>> It has no signs of life even though all the HAL settings are reverted >>> back to what they were, when motor did turn: >>> >>> # BLDC module settings >>> setp bldc.0.scale 4000 >>> setp bldc.0.poles 8 >>> setp bldc.0.pattern 44 >>> # setp bldc.0.frequency 0 >>> >>> # Hall sensor feedback into BLDC module >>> net motor.0.hall-1 hm2_[HOSTMOT2](BOARD).0.gpio.003.in => bldc.0.hall1 >>> net motor.0.hall-2 hm2_[HOSTMOT2](BOARD).0.gpio.004.in => bldc.0.hall2 >>> net motor.0.hall-3 hm2_[HOSTMOT2](BOARD).0.gpio.005.in => bldc.0.hall3 >>> >>> # position feedback signals >>> # net motor.00.pos-fb hm2_[HOSTMOT2](BOARD).0.encoder.00.position => >>> pid.0.feedback axis.0.motor-pos-fb >>> net enc.0.raw hm2_[HOSTMOT2](BOARD).0.encoder.00.rawcounts => >>> bldc.0.rawcounts >>> >>> # position command signals >>> setp hm2_[HOSTMOT2](BOARD).0.3pwmgen.00.scale [AXIS_0]OUTPUT_SCALE >>> # net motor.00.command pid.0.output => bldc.0.value >>> setp bldc.0.value 0.85 >>> >>> net pwm.00-a bldc.0.A-value => hm2_[HOSTMOT2](BOARD).0.3pwmgen.00.A-value >>> net pwm.00-b bldc.0.B-value => hm2_[HOSTMOT2](BOARD).0.3pwmgen.00.B-value >>> net pwm.00-c bldc.0.C-value => hm2_[HOSTMOT2](BOARD).0.3pwmgen.00.C-value >>> >>> >>> I would appreciate any suggestions, what might have happened. >>> >>> -- >>> Viesturs >>> >> >> What you did is not really good, you applied 85% of full motor voltage >> continously before you had the commutation worked out. This will likely >> result >> in overheating and shutdown of the 7I39, since you will get full peak current >> out of the 7I39 with the motor efecctivly stalled (step motor mode). It >> could have possibly damaged the 7I39 though this is not too likely. >> >> Peter Wallace >> Mesa Electronics >> >> (\__/) >> (='.'=) This is Bunny. Copy and paste bunny into your >> (")_(") signature to help him gain world domination. >> >> >> > > > Just curious Peter... but what would be a good value to start at? > 10-15% or so? > I don't have a 7i39 presently but I can see me getting one in the future. > > Dave
Normally the bldc.value would driven by the PID output If you use magnetic alignment the ini value woudl normally be say 10% for a bare bridge like the 7I39 (that is a low enough voltage that the motor resistance limits the current) > > > ------------------------------------------------------------------------------ > Keep yourself connected to Go Parallel: > INSIGHTS What's next for parallel hardware, programming and related areas? > Interviews and blogs by thought leaders keep you ahead of the curve. > http://goparallel.sourceforge.net > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Keep yourself connected to Go Parallel: INSIGHTS What's next for parallel hardware, programming and related areas? Interviews and blogs by thought leaders keep you ahead of the curve. http://goparallel.sourceforge.net _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
