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Author Topic: unwanted creep in jog mode?  (Read 13686 times)

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Offline comet

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Re: unwanted creep in jog mode?
« Reply #30 on: November 04, 2014, 05:42:45 AM »
ok Ive changed the computer and fitted a uc300,and the machine still creeps occasionally when using mpg's.
the only thing I can think of is that I use 2 mpg's and maybe theres a bug in mach's code?

Tony

Offline rcaffin

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Re: unwanted creep in jog mode?
« Reply #31 on: November 07, 2014, 03:47:43 AM »
That's not a bug in mach. That's a hardware bug. Why?
Because way back at the beginning you said that the Mach DROs were showing the creep. In other words, Mach was getting commands from somewhere to move.

There may be a bug in your MPGs, or there may be a bug in the hardware interface to the MPGs, or there may be a bug between you computer and whatever external engine (UC300?) you are using.

But there is a hardware bug somewhere. (Um - unless there are two bugs.)

Cheers
Roger

Offline comet

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Re: unwanted creep in jog mode?
« Reply #32 on: November 07, 2014, 08:23:20 AM »
Roger yes I see your logic, my mpg's are cheap Chinese ones. is there a debounce setting for the mpgs? or do I need to put capacitors on them ? could it be an earthing problem? when the creep happens it will continue until I switch mpg,s  so I guess it probably is an issue with a spurious puls from that area.

Tony

Offline rcaffin

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Re: unwanted creep in jog mode?
« Reply #33 on: November 07, 2014, 02:38:51 PM »
> is there a debounce setting for the mpgs?
Not to the best of my knowledge, but others might know better.

I am not sure the hardware problem has to lie inside the MPG. It could be a poor connection at the connector or inside your hardware. In particular I would check all the earth connections right through, then the power supply connections. Then i would check that the power supply can actually handle the load of the MPGs - does the rail sag at all when you plug them in?

Actually, I would start by testing the system withOUT the MPGs. Use the keyboard instead - that's all I use. If there is creep showing on the DROs without any MPG connected, you have a real noise problem in the rest of the hardware. Somewhere.

Cheers
Roger
CNC: one way to get it right; a thousand ways to get it wrong.

Offline comet

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Re: unwanted creep in jog mode?
« Reply #34 on: November 10, 2014, 05:38:53 AM »
it never creeps with the the mpg's disconnected, the creep only happens if you go from one mpg to the other too quickly and very rarely at that, im wondering how the mpg's could be putting out a spurious pulse train?, unless they are "dithering" under the correct circumstances.
    I couldn't possibly go back to keyboard only after the luxury of MPG,s !!

tony

Offline rcaffin

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Re: unwanted creep in jog mode?
« Reply #35 on: November 10, 2014, 06:02:02 AM »
Quote
it never creeps with the the mpg's disconnected, the creep only happens if you go from one mpg to the other too quickly
Ah well, that tells you where the problem is likely to be.
I would suggest checking that the main machine and the MPGs all agree on what is 'active' - HI or LO.

Quote
I couldn't possibly go back to keyboard only after the luxury of MPG,s !!
Um - you would prefer to have the MPGs and the creep in place of keyboard and no creep?
:-)

Cheers
Roger

Offline comet

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Re: unwanted creep in jog mode?
« Reply #36 on: November 10, 2014, 07:54:17 AM »
How do you alter the active high/low state?
yes as long as im careful it doesn't creep, which is far better than no mpg's, Ive learnt to live with it, its just sometimes it catches you out ! :o

Offline rcaffin

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Re: unwanted creep in jog mode?
« Reply #37 on: November 10, 2014, 02:42:34 PM »
> How do you alter the active high/low state?
Mach, config, pins&ports,MPGs ... SAVE CONFIG

Cheers
Roger

Offline comet

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Re: unwanted creep in jog mode?
« Reply #38 on: November 10, 2014, 05:08:19 PM »
cant see anything in there about active high and low, just ports and pins?

Offline rcaffin

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Re: unwanted creep in jog mode?
« Reply #39 on: November 10, 2014, 08:30:12 PM »
Ah - yes, I may have misled you a bit. My apologies. Wrong page.

The MPG page does not have any settings for active HI/LO, but are your MPGs using that page? It is possible that the MPGs on your Mach system is configured to use the Input Signals page instead, where the Jog signals at the bottom do have the option for Active HI or LO.

Come to think of it, how have you managed to put TWO MPGs onto your system - as you said earlier? Neither the MPGs nor the Jogs pages permit that. If you have confused poor Mach then anything is possible (but most likely NOT good)  :-)

Cheers
Roger