Using npn Inductive sensor for end stop.

Hi can someone tell me if mine are broken.
i cant understand these. They are stock part on the cnc machine.
And would like to keep it stock. 

here is one of the switches. Attached.

I use an new 7i76U board. And can easy just trigger the end stop pin with a wire from positive source (+)

Since this gives reverse. I did think to add a relay.
but the relay just stays on.

How do these work. I get constant 24 volt.
but when messure resistanse it does from 4ohm to 40ohm.
so something is happening. When it switches and led goes on/off too.

Anyone know these.
https://photos.app.goo.gl/jcqMZvWbBJQ8ZE1p6https://photos.app.goo.gl/jcqMZvWbBJQ8ZE1p6

Huh?

Please clarify.

What exactly do you intend to achieve?

To use NPN sensors with 7I76U inputs (which need a positive signal to actuate),
you must add a pullup resistor to each 7I76U input connected to a NPN switch.

+24V --> resistor_pin_1 --> resistor_pin_2 --> NPN output + 7I76U input

Suggested resistor value is 2.2K 1/2W

(PNP sensors need no additional components)