On Wednesday 22 February 2017 01:51:15 Valerio Bellizzomi wrote: > Sorry for the confusion, I meant to ask if this configuration is good > for running with the SPINx1 > loadrt hal_parport cfg="0x378 out " setp parport.0.reset-time 2700 > loadrt pwmgen output_type=0 addf pwmgen.make-pulses base-thread > addf pwmgen.update servo-thread > net spindle-speed-cmd motion.spindle-speed-out => pwmgen.0.value > net spindle-on motion.spindle-on => pwmgen.0.enable > net spindle-pwm pwmgen.0.pwm => parport.0.pin-09-out > # Set the spindle's top speed in RPM > setp pwmgen.0.scale 1800
On my small mill, software step etc generation, this scale is set to the top speed the spindle can turn, so is 2500. If your spindle can do 6000, yes, 6000 > with say the scale set to 6000 rpm, it is going to work as is ? A couple things to consider, the most important related to the order of the addf's. This list is internally executed in the order encountered in the hal file. So I always do the base-thread addf's first, then list the servo-thread entries next just because its a bit of "organization". The actual processing you are constructing is two execution loops, the base thread executed many times for each pass thru the much slower servo-thread. Haveing a module processing data from a read above the actual port read inserts a one loop execution delay in processing that data, so unless you want a delay on purpose, the order is always the read at the top of the list, the data massaging in the middle, and the write of that data is always last in the addf order. The data twiddling can be a thousand lines below all this, but it will be executed in the order of the addf's. Delays in processing, then making use of that data affects the stability of the loop because the data is stale. Most noticeable when setting up the PID modules. I am not using a spinx1 on that machine, but a now elderly PMDX-101 version that is essentially a clone of the spinx1, but has a bunch of switches and a pot so I can control the spindle either by the gcode, or totally manually, forward and reverse just by flipping the switches. I do not know if current PMDX cards have that same functionality or not, but at the time I converted it over a decade ago, it was the most useful version extant. It obviously cost more, a lot more as those parts were top shelf all the way. The only problem I've had with the whole setup was that I blew motor fuses regularly long before the motor stalled, and eventually the switching transistor in the motor circuit blew. Rummaging around in my pile of dead computer PSU's, I found a transistor that looked just like it, but could handle 3x the voltage and 10x the current. Using static conrol measures (its a hexfet) I transplanted one of those to the motor control, added an amp to the fuse, and the blown another fuse problem has been fixed. > > Thanks > > On Tue, 2017-02-21 at 16:54 -0500, Gene Heskett wrote: > > On Tuesday 21 February 2017 12:15:22 Valerio Bellizzomi wrote: > > > From the LinuxCNC manual I see an example : > > > > > > > > > loadrt pwmgen output_type=0 > > > addf pwmgen.update servo-thread > > > addf pwmgen.make-pulses base-thread > > > net spindle-speed-cmd motion.spindle-speed-out => pwmgen.0.value > > > net spindle-on motion.spindle-on => pwmgen.0.enable > > > net spindle-pwm pwmgen.0.pwm => parport.0.pin-09-out > > > # Set the spindle's top speed in RPM > > > setp pwmgen.0.scale 1800 > > > > > > > > > is this sufficient to get the spindle going ? > > > > This would be for purely software driving, which generally cannot > > drive a machine to anything resembling high speeds when it is > > supposed to be making a G0 move. > > > > Thats is why the majority of us use a smart card, which in some > > cases can be its own breakoutboard too. Such is the case with all > > but one of my machines, and that one can only move around 8ipm > > cutting and 10 or so at full throttle. My stuff with more std > > interfaces can move 40 to 75 ipm without missing a beat. > > > > Also associated in the speed limits are the limited drive currants > > available from the parport. Getting 10 mills out to drive the > > stepper drivers doesn't turn on the opto's all that fast, so that > > contributes to the speed limit. Most of the accessory boards can > > sink 24 mills, easily turning the led on in the isolation circuitry > > of the driver. > > > > But the most telling in using a parport with direct drive is the > > pulse jitter, as indicated by running latency-test for half an hour > > or so. Every time you see a spike/raise in the displayed time of the > > base-thread, thats a long step, and the motor may well stop while > > waiting for the next step, but when the cpu, even running an rtai > > kernel, will then try to catch up when it does get free of whatever > > it was doing, but the motor isn't able to re-accelerate that fast so > > it stalls. And everytime it stalls, you have a damaged or wrecked > > part. > > > > That makes spending the sheckels for a smart card interface very > > much desirable. If that interface can also be the BoB, thats a > > desirable economy. There are several mesa cards that meet that > > criteria, and I'm fond of the 7i90HD, which gives you a big pile of > > very steady heartbeat signals, as high as 8 stepper drivers, 4 pwm > > generators, and 4 encoder inputs. What you do not use, can be > > removed from the load > > configuration, and those pins then used as General Purpose I/O, for > > a grand total of 72 of them. The 7i90 can be driven by a std EPP > > capable printer port, (yours may or may not be EPP capable, and > > mainboard manuals do not always state the truth) or by an SPI port. > > > > So please reconsider how you are going to interface to the > > machinery. Getting some isolation between the computer and its > > jitter pulse generation is something you'll never regret. Ping? > > > > Where on this ball of rock and water are you? Cheers Valerio Bellizzomi, 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
