Homing sensors issue with parallel port BOB

Hi everyone.
I'm wiring the control box of my 3d printer, and i need to connect the 6 limit switches / homing sensors to a common pin of the BOB.
The BOB is this one:
warp9td.com/images/BOB_Vendors/StepperOnline/ST-V2.pdf
As stated in the pdf the input pins of that board are 12-24 volt tolerant, so i connected the output of my sensors (connected in series to each other) to the GND / P13 pins.
The problem is that the value read from Linuxcnc for that pin is always TRUE (or false if I invert it).
Do you have any idea of how to set up this kind of configuration?

This is my hal setup:
net XYZ-lim parport.0.pin-13-in-not => axis.0.pos-lim-sw-in
net XYZ-lim parport.0.pin-13-in-not => axis.1.pos-lim-sw-in
net XYZ-lim parport.0.pin-13-in-not => axis.2.pos-lim-sw-in

net XYZ-lim parport.0.pin-13-in-not => axis.0.neg-lim-sw-in
net XYZ-lim parport.0.pin-13-in-not => axis.1.neg-lim-sw-in
net XYZ-lim parport.0.pin-13-in-not => axis.2.neg-lim-sw-in

net XYZ-lim parport.0.pin-13-in-not => axis.0.home-sw-in
net XYZ-lim parport.0.pin-13-in-not => axis.1.home-sw-in
net XYZ-lim parport.0.pin-13-in-not => axis.2.home-sw-in


Thank you very much

Do you know if you have PNP or NPN sensors? Is there any guidance on what type of input the ST-V2 expects? I started with that BOB, but gave up after hitting limits in my design and the very minimal documentation for things like that, so you might have to hunt for an answer. In my case, I had NPN sensors and had to use pullup resistors on the inputs to get a the controller to recognize high/low differential.

I think you just need something like,
net XYZ-lim parport.0.pin-13-in-not => axis.0.pos-lim-sw-in => axis.1.pos-lim-sw-in => axis.2.pos-lim-sw-in
The signal can have lots of destinations, but only one source.
You need power on the 12-24V Power Supply. Is pin 13 being pulled down to GND / released at limits, by the sensors.

I'm using PNP NC sensors, that i connected as in attachment.

That way when i put something close to one of the sensors, all the following ones get disconnected and i get 0v between the black and the blue wire. Is it correct? It looks correct by looking at the lights shutting down behind the sensors...

@raglanlittlejohn I just discovered that i have to connect those 2 pins form the comment section of a youtube video....
The problem is that with those 2 pins connected to the power supply, and the final black wire of the sensors chain connected to pin 13, the light on the sensors won't shut down completely when i put an object in front of them (they just dim, and that makes me think that i'm doing something completely wrong).

thinking at how a pnp nc sensor works, i'm starting to think that i need a pulldown resistor

It doesn't seem to work that way.
However my sensors are pnp nc, they should be putting out supply voltage until they trigger, shouldn't they?
I tryed with 1 signle sensor and that way it works (however i get en error if i try to "simulate" the homing process by hand, but that's not the main issue now).

mmm
i'll do more experiments tomorrow (now it's 1.40AM here).
Thank you for your help!