Hello Guest it is April 21, 2021, 02:32:21 PM

Author Topic: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,  (Read 3733 times)

0 Members and 1 Guest are viewing this topic.

error message as soon as its starts to cut it stops an throws this error....

>>>Clearing a spurious limit hit latch event, Start logging in menu Diagnostic Logging to see more detail,....<<<<

 i tried that diagnostic logging... i belive i did... if im in right area,... an i didnt tell me anything unless im not using it right,.....i thought maby my motors are moving to fast so i turned them down... same error,  works if i cut air but the min i start cutting aluminum it throws this error,....im at a lost as what its referring too??? its like it knows it is cutting but it never lets me go any farther than the  start ofo ,               the cut, im going slow as possible but same error..????wth???
Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #1 on: June 24, 2018, 08:32:37 PM »
Hi,
sounds like electrical noise, almost certainly from your spindle, propagating to one or more
of the limit switch circuits.

Are you using Mach3 or Mach4?

You could try increasing the de-bounce in Mach3 or increase the filter time in Mach4.

Craig
My wife left with my best friend...
     and I miss him!
Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #2 on: June 24, 2018, 08:35:14 PM »
Hi,
the spindle really starts producing noise as it comes under load....ie cutting.

What kind of spindle and spindle drive do you have?

Craig
My wife left with my best friend...
     and I miss him!
Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #3 on: June 24, 2018, 08:37:26 PM »
IM Using a kbmm 225d with a tread mill motor,... on mach 4, i have tried 3 diffrent plugins as well, its been throwing limit switches errors as well
Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #4 on: June 24, 2018, 08:59:39 PM »
Hi,
that speed control is fairly noisy, its a phase controlled bridge rectifier.

As an experiment try plugging your speed control into a different (different circuit)
than your PC and CNC machine. It may be that the noise transferred back into the mains
is getting into your machine.

Other than that you are going to have to filter both input and output of your speed control.

Have you tried increasing the filter time in Mach4? Stopping the speed control from producing noise
is the best solution. Increasing the filtering on your signal (limit) lines is often effective but not the first
line approach.

Craig
My wife left with my best friend...
     and I miss him!
Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #5 on: June 24, 2018, 11:44:50 PM »
My motor speed controller is plugged into s different outlet, how do you filter input an outputs in mach 4,? Also im not running my speed control through mach 4, im using the speed control knob an power switch, i havent  added spindle control to mach yet,...i did notice without limit switches on it doesnt do it... i re routed my wires to limit switches but it didnt change anything
Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #6 on: June 25, 2018, 12:24:01 AM »
Hi,
the electrical noise is being generated by the speed controller and your spindle motor.
It is being radiated to your signal lines in your machine. They are sensitive. A big
noisy (electrically) motor running right next door will induce small voltages and currents in signal
lines close by.

You can jump up and down and blame Mach if you wish but it wont do you any good, this is
physics...you could blame James Clerk Maxwell (1831-1879), the 'father' of electromagnetics...
but hes just a little bit dead at the moment!

Good practice put all the high power lines like your spindle wires as far away from Machs signal lines as possible.
The next best practice is to put filters on the input and output of your speed control. If you have
a VFD you MUST follow manufacturers recommendations or you will blow your VFD up.

Your speed control is very much less high tech and good line filters will help a great deal without risking
your speed control.

The next technique is to reduce the sensitivity of the signal lines to electrical noise. If you have a look on
the ESS Config plugin, Pins page you will see that inputs have a filtering setting. Try putting a setting of 100
say in each of your limit switch inputs. It may help.

Best practice is to prevent your speed control generating noise ie line filters, next best is reducing the coupling
of noise into your signal wiring, ie physical separation and screening, the next best is introduce filtering on the inputs,
ie the software filter I've mentioned and/or RC low pass filters on the pins.

Craig
My wife left with my best friend...
     and I miss him!
Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #7 on: June 25, 2018, 12:29:53 AM »
Hi,
this sort of thing:

http://nz.element14.com/schaffner/fn2020-20-06/filter-20a-chassis/dp/1191370

Ideally one on the input and it wouldn't hurt to have one on the output too.

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

Offline Stuart

*
  •  261 261
    • View Profile
Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #8 on: June 25, 2018, 02:33:30 AM »
To the OP

Do you have all the equipment equipotentialy bonded with at least a wire of 6mm csa

You need a good odd order harmonics filter fitted to your spindle drive input it the 9th harmonic that does the damage

All low level signal cables should be shielded with the braid only bonded at one end

Re: WHATS THIS ERROR..??? Clearing a spurious limit hit latch event,
« Reply #9 on: June 25, 2018, 07:46:42 AM »
As Craig mentioned the first line of attack should be physical separation and shielding, especially for the power leads from the speed control to the motor.

The filter recommended by Craig may work for a phase angle controller for DC motors such as the KBMM but beware using them for a VFD.

VFD's generate high levels of harmonic current and generic noise filters may not survive usage on a VFD, especially on the output because the internal capacitors may overheat. In that case I would recommend instead that you put a generic filter, such as the one that Craig recommended in the link above, on the input power for the control board and the host computer and monitor. Then put a large simple ferrite ring common mode choke on the output and possibly the input of the VFD.
Steve Stallings
www.PMDX.com
For PMDX product support, please use PMDX forum or direct email for quickest response. We do not use this forum as our primary product support site.