Axyz retrofit - limits and homing

Please excuse the n00b questions as I work to setup my small AXYZ cnc router. Does anyone know how I should
implement limit switches in Linuxcnc? The factory wiring of my old millennium cnc router has a single blue tipped inductive proximity limit sensor on each axis. The sensors are located at the top of the z-axis, front of the y-axis and left on the x-axis. Each sensor has connections notated sig, 12v and ground. 

My assumption is that these are NPN, Normally Open (NO), but will confirm:

• Normal state (no metal detected): Sig wire outputs ~12V

Activated state (metal detected): Sig wire outputs ~0V

Two questions:
1) Will these play nicely with the 7i96s card I’ve ordered?
2) Are these be sufficient for homing the router? 
 

1. yes
2. yes
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Mesa 7i96S can have inputs set as active low or active high, so pretty much any sensor works.
LinuxCNC can use a single switch to do homing and both limits for any of the axis/joints.
Do download and read the Mesa manual while connecting sensors, it will save you a lot of time.

Thanks for the reply. I have LinuxCNC installed on a computer now but I’m still waiting for the Mesa card to arrive (should be this week). When you wrote ‘Mesa manual’ do you mean the ‘7i96s Ethernet Step/Dir Motion control interface’ document? If so, I’ve read it but will admit to not fully understanding all of it (yet).

Yes that is it, and sorry forgot to mention, read until Host Interface section.