Noob here.  I know very little about wiring, luckily the machine I bought is mostly done.  I want to add limit switches.  Can someone tell me how to wire the switch to this board (trying to post pic also).  It is a PM25 originally done by Procutcnc.  I am the second owner, Procutcnc will not respond to me, the previous owner warned me that their customer support was ZERO.  Hoping someone can give me a quick answer as to where the two switch wires should be plugged in to the board.  The board has 4 spots for each axis (+24v, in-, in+, 24vgnd).

You have an industrial controller so you should try something better than using 2 wires (mechanical) switches.

Attached is wiring for 3-wires  NPN and 3-wires  PNP sensors.

Thanks for the response.  How do I know which of your examples applies to my board.  I did a little internet searching and am more confused.  Anyone out there have a Procut CNC version of the PM25 with limit switches that could share a pic with me??

You already know on the left of your picture, are limit/home switch connections for your machine.
Left Topmost is X axis and left bottom most is S axis= A axis in MACH3.

So each axis has +24v, in-, in+, 24vgnd.
Assuming you use the NPN Sensor,
you connect +24v of the sensor to +24V of that axis on the board
you connect -24v of the sensor to 24VGnd of that axis on the board
and for NPN sensor you connect the im to in- of that axis on the board

For PNP sensor,
you connect +24v of the sensor to +24V of that axis on the board
you connect -24v of the sensor to 24VGnd  of that axis on the board
and for PNP sensor you connect the im to in+ of that axis on the board

If you are using simple NC (normally closed) mechanical switches system,
You will need a 1K or 10K OHM resister for each axis.
Connect +24V with the 1K or 10K resister to im+
Connect the other end of the switches for that axis in series to 24VGnd  for that axis on the board.
I will test with 10K OHM first to save power. But if that does not work, then use 1K OHM.

Thank you soooooooo much.  I will get one of each, NPN and PNP, and try them wired as you suggested. Thank you for simplifying it for me, much appreciated!!!!

I wired in a pnp nc switch, light is on, light goes out near metal.   Appears to be working.  How to configure ports and pins in mach3?  On the diagnostic page a yellow light is on beside the switch but when i jog in either direction and activate the switch nothing happens.  All the examples I found reference a BOB.  My switches are on the main ST10 servo tec (industrial board).  The only other thing in my cabinet is the ESS board.  Any suggestions??

Please just take this clue:-
Dedicated Input Pins of ESS are
Pins 10, 11, 12, 13, and 15 of all 3 ports
They all are ACTIVE LOW meaning when there is a 2.5V to 5V on the pin is is NOT active. When pin is low 0-2.xV the the pin is active ie limit switch is triggered. So in MACH3, limit switches pin MUST be set ACTIVE LOW for sure.
But which pins?
If you know which pin is e-stop (say it is pin #15) then you can guess that X , Y, Z, A limit switch are pins 10, 11, 12, 13 respectively.

A bit of experiment while looking at the diagnostic page of MACH3 is all you need to do.
If on the diagnostic page a yellow light is on mean you must change to set the pin active low (instead of active HIGH now).

Reuel

Again, thanks.  I got it to work, in part by doing just as you said.  The biggest problem was that the board seems to be reversed, it is labeled 24v and 24 neg but the switch would not work until I reversed those.  I tested with a 9v battery and the switch worked exactly like the diagram it came with, when I put it on the board it would not work like the diagram until I reversed it.  Weird.  I concluded that the board it labeled wrong.

Congratulations

Before you conclude labeling is wrong, Could you check with a multimeter set to DC >50V scale to determine which is +ve and which is negative.
Perhaps between those 2 connections, it is +48V rather than +24V.
If it is +48V (whichever way) rather than +24V, you have to make sure that your sensor can take 48V or it could get burnt out quickly.

When I tried to wire two switches I can’t get them both to work on the same input, only one.  I tried every combo in all the posts I found.  How should pnp’s be wired so each can trip independently?