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Author Topic: Licensed version, will increasing kernal speed prevent missed charge pump pulses  (Read 700 times)

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I have been testing the demo version of Mach3 Mill, mostly positive so far. When I monitor the charge pump signal, every second or so it drops a pulse, reducing the frequency to 6.25kHz for one cycle. This plays havoc with my watch-dog hardware that is looking for a 9-15kHz signal.

I'm presently running the kernel at 25kHz because of the demo version limitation. If I purchase a license and then increase the kernel speed, will the dropped CP pulses be fixed?
Hi,
very few people bother with the charge pump anymore.

I don't believe that Mach differs between the Demo and Licenced versions so I would not expect that isse to be resolved
with a licence.

Craig
My wife left with my best friend...
     and I miss him!

Offline ger21

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I would run Drivertest.exe in the MAch3 folder and check the results. Disregard the messages, and watch the pulse rate and the graph.

As Craig said, I wouldn't expect the license to make a difference with the charge pump. My guess is that the PC your using may not be ideal for running Mach3.
Gerry

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I ran the driver test, selecting 25kHz, 45kHz and 100kHz.  The results look the same, suggesting that the setting does nothing in demo mode.

When I run mach3 with 45kHz selected, motor still moved correct distance, also suggesting the 45Khz setting is doing nothing.

When I tried running Mach at 100kHz, Mach crashed on start-up, suggesting perhaps it does do something??

Does anyone know for sure?







« Last Edit: April 13, 2018, 09:46:00 AM by slow-poke »

Offline ger21

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I think that demo mode is limited to 25Khz. Not sure though?

Frequency would have no effect on distance traveled. Kernel speed is just the maximum number of pulses per second Mach3 will allow. It basically changes the speed that Mach3 runs at internally.

Distance is still determined by steps/unit, and speeds are still controlled by the Velocity setting.
« Last Edit: April 13, 2018, 09:55:39 AM by ger21 »
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
I think that demo mode is limited to 25Khz. Not sure though?

Right you are. Once licensed, that restriction (and other demo mode limitations) is lifted and you can set a higher kernel frequency. The full list of demo mode restriction can be found here: http://www.machsupport.com/software/mach3/

-Bryanna
Newfangled Solutions Helpdesk: http://support.machsupport.com
YouTube Support Channel: https://www.youtube.com/c/MachSupportOfficial
Hi,
as Bryanna has pointed out mach3 Demo is limited to a kernel speed of 25kHz. The good news is that your PC will do a better job at 25KHz than it will at a higher speed.

Back when I used Mach3 and a parallel port I would from time to time experiment with increasing the kernel speed. Everything about Mach got worse as I did so. The ONLY time
you would increase the kernel speed is if you need Mach to produce pulses really fast to accommodate a servo with a high count encoder or your are trying to read a highspeed
MPG or encoder.

The bottom line is...don't bother. If you need high speed pulse streams or need to read a highspeed encoder/MPG get yourself an external motion controller like a SmoothStepper, it
will read/generate pulses up to 4Mhz, 160 times faster the Machs parallel port!

As far as a charge pump goes, I don't use one and have not bothered with one for five years without problems. They were supposed to turn the machine off (power input) if the PC stopped
talking to Mach, it doesn't happen that much, if at all. Likewise there is a feature called a 'watchdog timer' in Mach left over from caveman days that no one uses any more either.

There are many more interesting a productive things you could be doing with Mach than trying to get the charge pump to work perfectly.

Craig
My wife left with my best friend...
     and I miss him!

Offline ger21

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I can say that I've heard from many people over the years that have had the opposite experience, claiming that Mach3 ran much better at 35Khz or 45Khz.
But this should have nothing to do with the OP's original issue.

And I believe the purpose of the charge pump is to prevent the outputs from toggling on and off before Mach3 had control of the machine. It's still very useful when used in a safety circuit to not allow powering the machine until Mach3 has control. Imo, it should not be used as a safety in the case of Mach3 or the PC crashing, because there's no guarantee it will still be working at that point.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html