Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Podbuilder on January 07, 2022, 06:51:00 AM

Title: Mach 3 - Two types of Probe - Active low and active high - how to have both?
Post by: Podbuilder on January 07, 2022, 06:51:00 AM

Hello,   

I've been using a G540 with a touch off probe to set my z axis (active low) for a few years.   I recently made a touch probe for non-conductive materials. (x/y axis)  (active high)  Apart from going into the settings every time and switching the probe from active low/high and back is there any way to set this up?  Even moving the a toggle button for active low/high onto the home screen would be handy.  I've used screen4 to do some basic stuff so willing to have a go but cant find any material on how to toggle the active low/high probe in code.

The G540 is 12v at the inputs and a Not gate circuit was suggested but not sure how to wire this up. 

Any suggestions.

Thanks.

Title: Re: Mach 3 - Two types of Probe - Active low and active high - how to have both?
Post by: Graham Waterworth on January 07, 2022, 10:01:39 AM

Make the probe activate a relay

Title: Re: Mach 3 - Two types of Probe - Active low and active high - how to have both?
Post by: Podbuilder on January 08, 2022, 10:22:27 PM

So I think I'll just make a base touch off probe with the same mech.  Problem solved.

(https://hosting.photobucket.com/images/j7/Spidey4fun/Pic.jpg)

Title: Re: Mach 3 - Two types of Probe - Active low and active high - how to have both?
Post by: joeaverage on January 09, 2022, 03:26:30 PM

Hi,
with Mach3 you will struggle to have two probes. What you are in effect required to do is use an auxiliary output to switch a relay between two independent probe
circuits, one circuit ill require a logical invert so that as far a Mach3 is concerned there is only one probe.

Alternately step up to Mach4 where there are four independent probe inputs.

Craig

Title: Re: Mach 3 - Two types of Probe - Active low and active high - how to have both?
Post by: Podbuilder on January 09, 2022, 05:40:44 PM

Hi Craig,

I've a single plug above the spindle.  I'll just choose the desired probe.  I've a few different macros set up for probing.  It should be fine.

Made from parts sitting around the workshop.

(https://hosting.photobucket.com/images/j7/Spidey4fun/PXL_20220109_224220772.jpg)

Cheers
Brad.

Title: Re: Mach 3 - Two types of Probe - Active low and active high - how to have both?
Post by: joeaverage on January 09, 2022, 06:31:24 PM

Hi,
 yes plugging the probe in to the right socket will do the trick, but Mach is expecting either a normally closed or a normally open contact. Both probe will
have to be the same....which may in turn require a 'logical invert' but into one of the probes.

Craig

Title: Re: Mach 3 - Two types of Probe - Active low and active high - how to have both?
Post by: Podbuilder on January 09, 2022, 06:55:37 PM

Yes.  Both are now the same.  I was using a aluminium touch off  block (active low)  both these will be active high.