Help Needed on Debounce

[Bob Hepple]

I have a new system and put mach on - the problem is the  stop keeps lighting up and stopping everything debounce was set at 3000 so I uped it to 4 still not good then uped it to 5000 and sstill trigers happen  ruffly every 4-5 mins I thought 5000 was as high as I should go unless you all know different, and I thought this might have an underlying problem.

p.s pc has  an atom processor built onto the board.

Help

[BR549]

Is there any error messages shown when it does it.  Sounds like  NOISE or ground loop problem.

(;-) TP

[ger21]

You can crank it up to 20,000 or higher if you want, but the higher it's set to, the longer the delay before Mach3 sees the switches close.
As Terry says, you probably have a noise problem, and fixing it is a better option than a very high debounce.

[Tweakie.CNC]

Bob,

It would help if you connected a 0.1uF (small ceramic type would be OK) capacitor between each input terminal you are using for your switches and ground (GND or 0 Volts).
This should reduce the noise pickup and enable you to run with quite a low de-bounce setting.

Tweakie

[Bob Hepple]

Thanks Chaps I also think it is noise but going to check wiring to the emergecy off switch,  I am going to run mach and see if the request still happens (without running mill and cutting obviously)
if the request still comes back then theres issues . because the way my mill is placed I have to have long wires to the control box could this also be causing the problem?? TWEEKIE I also was thinking about putting some type of filters on and I think it would be better on than off. I don't know nothing about electronics but in RC Racing I used to use 0.1 Microfad capacitors on dc motors to stop noise are these what you talking about..   

[Tweakie.CNC]

That's the ones Bob.

Packs of them are available on EBay for small money. 

Tweakie.

[Bob Hepple]

Tweeky thanks the reason I asked so specifically regarding Rc is I have a lot of these lying around from the Old RC days they are ceramic and will fit these for a matter of course and try again after checking wiring. Do you think the length of cables could be an issue???

Also looking on the forum about infomation on fitting limit switches...

Bob

[Tweakie.CNC]

Bob,

Length of cables are an issue but as long as they are screened and correctly terminated you will be OK.
Limit switches must be connected with screened (shielded) cable with the screen connected to GND at the controller end only. A single point GND for all common connections is also good practice.

Tweakie.

[Bob Hepple]

Tweakie sorry for the  newb question BUT the filter's you said put between each input terminal I am using for my  my switches (grnd or 0 volts) do you mean the drives for the motors if not where exactly are we talking about in Lay mens terms.

[Tweakie.CNC]

Hi Bob,

One wire from a  capacitor goes to the same terminal as the switch is connected to and the other wire from the capacitor goes to GND.
Fit one for the EStop wire and every other limit switch that you have connected. They are fitted at the controller end (usually the breakout board).

If you post here or email me a copy of your wiring diagram I will indicate where they are fitted if you are still in doubt. 

Tweakie.