hal_manualtoolchange as signal for manual tool change button close to spindle

I want to have a button close to my spindel with a light to change the tool by hand (no automatic changer available for now). Thinking about how to activate this button (the light should indicate, that the button can be pushed to change manually - so spindle is at thero speed and disabled and..)

Now I found this hal component. Could this be a way of how I can "supply" / "activate" my button / light?
That means I will have to do a tool change by entering the m6 command in the mdi line each time right? But the bennefit of the hal file will be that linuxnc is checking if motion is stopped and will wait to accept a spindle run until I press continue / tool change is ready. So I could make sure my hands are safe during change.

Is this a good idea to use it in my case or bad?

Please notice the sketch of attached of the button, light and tool clamping valve.

You can add a VCP panel with that button, link it in hal to the physical button and also make it do whatever you want, so issuing an M6 is easy, having it also check if the spindle is at 0 speed or disabled is a bit more work, about 3 to 5 lines in hal, probably.

VCP means Virtual control panel? So adding a software button?
I just want to go by a physical hardware button. Direct connected to the valve for unclamping the tool like in the schematic.

Could you explain a bit more in detail?
My though was to i could maybe go with the hal_manualtoolchange.
If hal_manualtoolchange.change bit in (Receives signal to do tool change) is active I will foward this to an output of the mesa card to supply my button.

you need an input for the button and and2 it to the tool change pin.
The output from the and2 would be connected to an output pin that triggers your relay or whatever. 

The tool change HAL pins are:

Information about those pins are here:
linuxcnc.org/docs/html/config/iov2.html

JT

Ok. I think I got it.
That means I have to change my wiring by wiring each signal (button and valve) to the IO card and manage it via linuxcnc.

Will check it out during the weekend.
Thanks for now!