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limit switch config
« on: April 22, 2018, 12:37:58 PM »
I'm running Mach4 with the Pokeys57CNC board and I recently wires limit- switches for X, Y, and Z axes. I'm now having trouble configuring the switches in Mach4 and I could use a little assistance. All 3 limit switches are wired NC and I've already checked continuity, so I know the wiring is correct (switches are wired in parallel, by the way). I connect the limit switch wires to the Pokeys57CNC board via a DB9 connector that translates to the 20 pin flat cable IDC socket connector that plugs into the dedicated port on the Pokeys board, and I've checked that wiring from the DB9 connector to the 20 pin connector on the Pokeys board has correct continuity as well. Therefore, I believe I'm solid on the hardwiring aspects and my issues all lie in Mach4 software configs.

When I start Mach4, I immediately get a "Limit switch -- tripped!" warning for X, Y, and Z axes and that prevents the Pokeys pulse engine from starting and functioning properly. Again, this tells me that I have a software config issue that is preventing proper communication. Could someone walk me through what Mach4 settings I should be using both in Configure > Mach...? Do I need to focus only on the Output Signals tab here? Also, what about settings in Configure > Plugins... > PoKeys plugin - PoLabs? I assume all focus here is on the Pulse engine page settings, correct? I currently have all the Limit- switches set to Ext. dedicated as specified in the Pokeys documentation.

When I get through all of these, I hope to have created a tutorial for others to follow as this has been really challenging to work through! Any advice provided is greatly apprecaited.

rndpig
Re: limit switch config
« Reply #1 on: April 22, 2018, 08:49:42 PM »
Hi,
I'm confused....are you trying to set up limit switches or home switches?

Limit switches are at each aend of each axis and are to prevent the machine from crashing into the endstops.
Two switches per axis, three axes, ergo six switches.

Home switches give the machine a reference point, one switch per axis, three axes, ergo three switches.

You have a ton of inputs with the PoKeys board, you'd be best to put one switch per input, it saves confusion.

I'm not familiar with the PoKeys plugin but I would expect the Inputs Page of the Mach plugin would have
three home inputs checked, if you are indeed trying to use these switches as homes, or six inputs checked
(X++ X-- Y++ Y-- Z++ Z--) if you want to use limits.

Note if any of the limit inputs is triggered Mach shuts down...thats what it supposed to do. It means that one or more of
your switches is triggering a safety response from Mach when you are turning the machine on. You need to clear
that fault before Mach will properly wake up.

Craig
My wife left with my best friend...
     and I miss him!
Re: limit switch config
« Reply #2 on: April 22, 2018, 09:25:12 PM »
Craig,

I've only installed limit- switches for now, and these will double as home switches as well. I will ultimately use soft limits for limit+ boundaries, so I'm really trying the simplest of setups. I'm needing input from someone who knows both Mach4 and the Pokeys interface when it comes to the pulse engine. These are the settings that are throwing me right now, though I'm glad to have continuity on the NC switches that I've wired.

rndpig
Re: limit switch config
« Reply #3 on: April 22, 2018, 09:27:57 PM »
Hi,
so have you installed three switches or six?

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

Offline dude1

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Re: limit switch config
« Reply #4 on: April 22, 2018, 11:33:44 PM »
rndpig I gave up trying to get them working as home and limit switches and just redid the wiring to have one at each connection, I could get it working in the pulse engine but as that's only for testing with the pokeys57cnc it means bugger all.
Re: limit switch config
« Reply #5 on: April 23, 2018, 07:20:57 AM »
I've installed a total of 3 NC mechanical limit switches that will serve as the limit- points. No limit+ switches nor home switches have been installed. My intent is to only ensure that the gantry doesn't crash into the CNC housing, which is where there are only limit- switches in my setup.
Re: limit switch config
« Reply #6 on: April 23, 2018, 02:49:06 PM »
Hi,
three switches would protect one end of an axis (three axes) OK.

If you used them as home switches however then you can use soft limits which would protect against out of bound excursions an all axes. Soft limits work well but
having three physical limit switches is an absolutely sure to provide protection.

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

Offline dude1

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Re: limit switch config
« Reply #7 on: April 23, 2018, 04:17:47 PM »
you mean 2 for X and Y negative limit and one for Z plus limit, if so just wiring into the 57cnc should work as long as they are all around the right way, I will have a look in a minute what way around I did mine