Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Mcgyver on March 08, 2008, 03:11:19 AM

Title: mach3 problem with operator interface
Post by: Mcgyver on March 08, 2008, 03:11:19 AM
Hi everybody!

I hope I've posted this topic in the right spot.

I'm currently retrofitting my emco pc mill 50 to mach 3 witch a bob board from

Everything works well only for one thing:

I've made a controll panel on my emco using a operators interface and 2 rotary knobs also from cnc direct

One rotary knob i'm using to toggle the spindle speed, every "klick" on the knob alters the spindle speed 10% incremental and works just fine!

For the feedrate I configured 2 oem buttons and hotkeys to toggle the feedrate. When I push the keys on the pc keyboard the feedrate alters nicely  in steps of 10% incremental (100%, 90, 80 etc.)
When I program the rotary knob for the feedrate i have to turn the knob quite a lot to alter the feedrate instead of one klick= 10% incr.

I've tried reprogramming the operators interface, using another port on he interface, programmed the other knob for the feedrate etc.... But it stil workst weird.
The knobs are technically in order with no malfunction but mach reacts weird on the pulses of the rotary knob for the feedrate. The knob for the spindlespeed works fine!

Who has an answer, for this?

I hope someone can help me

Best regards


Title: Re: mach3 problem with operator interface
Post by: jimpinder on March 08, 2008, 03:53:40 AM
I take it the spindle speed has nothing to do with Mach3 - but is controlled by some other electronics.

Does the rotary switch put out a pulse, or is it continuously connected to the position it is at. Does it make before break, or break before make when changing. The only rotaries I am familiar with are electronics wafer types.

As you can see, Mach is designed to run through a keyboard, which has all the necessary debounce circuits etc already in. Keyboards are designed to put out pulses.

I can see the advantage of rotaries - because you can label and look to see where they are set - but a simple way would be to replace the feedrate rotaries with two external push buttons, feeding into the input side of the computer - and your present logic will require only a minor change.

Other than that I feel that you will have to analyse the signals coming out of your rotaries, and write macros to include signal debounce etc, the fact that they are on all the time (or whatever). (A simple problem could be - if the swtiches are "on" all the time in one position - that mechanical bounce is causing intermittent signals to your computer)

There are, on the market several hand held, plug in,  control panels that already do what you are trying - or are at least programmable to do it. They, I am sure will have got round all the "electronic" problems and might be the answer ( I have no idea of cost, however)

Title: Re: mach3 problem with operator interface
Post by: jimpinder on March 08, 2008, 03:57:29 AM
I have just read your post again -

If you have connected these rotary switches into your BOB - what signal do they give to the computer.
A rotary switch, by design, gives different values as it changes, whereas push buttons give a pulse.
How have you wired the rotary switch to differentiate between counting up and counting down???
Title: Re: mach3 problem with operator interface
Post by: Mcgyver on March 08, 2008, 04:02:30 AM
@ jimpinder

thanks for the reply,

The rotary knop isnt connected to the mach BOB I use.
If you click on the link below you will find my operator interface

The operator interface is connected in series with the cable from my pc keyboard.

I can add several buttons to the interface and program a keystroke from the pc keyboard.
So I dont have to write macro's for it.
The rotary knobs give oute pulses that will simulate pushing a button on the pc board in my configuration I'm using them for spindle speed and feedrate.

You are right that the spindle has nothing to do with it because I'm altereing the values by software and not with a normal potentio meter trough my mach BOB.

Best regards

Title: Re: mach3 problem with operator interface
Post by: jimpinder on March 08, 2008, 04:42:10 AM
Sorry- I missed the operator interface the first time I looked at the site. This is certainly an interesting board.

Right - where to start. If you have used the OEM's and got them working via the standard key board, I would, I think wire up a couple of push buttons to your interface and try and "convert" them first.

Does the operators interface have preselected codes for each of the 32 inputs ???
I would, I think use Mach 3 against itself - Try going into Config/Hot Keys and selecting one of the jogging inputs - use A B or C, I don't think it will matter - and instead of pressing a key on the key board, toggle your rotary switch or press a switch on your interface and see what scan code it is putting out - and more important - is Mach3 picking it up.  I don't know if you have written any code for the OEM's but it may be that the scan codes need sorting out.

At least, if you can see that Mach3 is picking up the scan codes from your interface, we should be able to work out how to get it to do what you want.

Title: Re: mach3 problem with operator interface
Post by: Mcgyver on March 08, 2008, 04:55:56 AM
ok i'll try that.

I found the oem codes in the mach wiki they are 108 and 109.

The interface hasnt got preselected codes, you heve to tell the interface what keyboard buttons he has to simulate.

I can add up to 24 buttons and 4 rotary prints to the interface (now i already have 23 buttons hooked up which are all working, jogging functions etc)

The way to program the board is first to push the desired button on the keyboard and then pushing the knop on my controll board. the rotary buttons are the same.

First I'll try connecting 2 regular buttons to the  rotary input and see what happens. maybe the ratary's are to fast or something...