Limit Switches, EStop and Spindle

1) As I know HAL Show doesn't have realtime reload. I don't see changing of the variable in it.
Insteat of HAL Show I use HAL Meter.
Try HAL Meter for this reason.

2) As for inductive sensors they could not support resistor connection because of lack of the power.
In the past tried to connect inductive sensor in parallel of PLC input and Relay Coil. I was insuccesful in this. PLC input doesn' saw the change of inductive sensor. So only Relay Coil or PLC Input. In your situation you are doing the same but only with resistor (not inductance).

So as Summary:
-use hal Meter to look the state of variable
- to change that variable use short wire between P10 and GND. It's possible that you have damaged your P10 input, so reconfigure to P9.
- if you have succeded then buy NPN sensors and that one live for arduino.
- else if not, then I don't know what, maybe buy another board for this
- else if not, then don't use e-stop and limit switches and try to use without them. On my CNC 2 years I succesfully work without any limit switch and E-stop is only for button Turn-on. If you know how to work on CNC router, you don't need any limits and E-stops.

Maybe silly question
On the GND of your inputs you use a red cable. Is this positiv voltage (and high enough for your optocoplers to see it) Why not black for ground?

Hi Mike,

I'm guessing you are referring to the the pin 10 - Estop - GND wiring.
Just happened to have a red cable already attached to the Estop switch.
I'm currently waiting for a different Parallel Port Card to arrive as all the fault chasing and testing seem to be pointing in the direction of a dodgy port.

No
I ask for the screw connection GND. Is this ground of the switches and do you "input" enough voltage/current for the inputs?

I think I may be misunderstanding you.
The Inductive sensor signal wires are black and go to Pins 12, 13 and 15 on my BOB. If you are looking at the photo of my BOB, the other thin red wires are the 5 volts (TTL) in to the board and the 5 volts out to the stepper drivers.
The other thicker black and red cables (at the top of the board) are 24 volts in for the board itself and then out for the limit switch supply.
The voltage change at pins 12,13 and 15 is from 9 to 0 volts when a switch is activated.
So the GND screw connection for the limit switches is at the top of the board (one of the thick black wires)

I think that you have to have GND (bottom in your image) connected to the ground of your 9V (as I interprete) this lower screw terminals are normally isolated from the rest of the board via optocoplers..