Axis GUI - Activate Power-On with External Pushbutton

RPi 4/B, 7i96, and Debian/Raspberry 2.8.4 iso with Axis Gui.
PncConf only used so far.

Just starting into Hal.
E-Stop built-in works quite well, but I would like a slight variation.

The E-Stop PB is hardwired to de-activate stepper supply, and I/P to LCNC to de-activate it.
Machine enabled is wired to reset the power supply to the steppers.

Recovery is to reset the E-Stop PB and select Power-On on the Axis Gui, and as expected, back to a running machine.

But, my control station has a PB labelled "E-Stop Reset" that was meant to achieve the same recovery action.

If I delve into the Axis/Hal documentation, can I expect to find a way to link the E-Stop Reset PB to the Power-On box on the Axis Gui ?

I have started reviewing the available Hal Documentation, and I am at a loss on where to start.
Could someone give me a hint and a nudge towards where to look  ?
 

I would suggest to have a look at HALUI here: linuxcnc.org/docs/html/man/man1/halui.1.html
You will find halui.machine.off , halui.machine.on pins. As well as some halui.estop pins that you can use.

Thanks JPL, just the nudge I needed.
I will report back with my proposed solution.

Well, that didn't take much effort or time.
PnCConf:
Entered Machine-On for Input 001 on the 7i96.

Result on HAL:
net Machine-On <= hm2.7i96.0.gpio.001.in

Entered in Custom Hal:
net Machine-On => halui.machine.on

On Machine:
Labelled the PB as "Machine On".

Not the E-Stop Reset I thought I wanted, but a very satisfactory result.
Machine operation is satisfyingly normal.

I'm assuming you have an external safety relay with a pushbotton for estop reset.
Your estop reset button should trigger a relay which sends field power to a input connected to
iocontrol.0.emc-enable-in

<code>
net Machine-On = hm2.7i96.0.gpio.001.in
net Machine-On = iocontrol.0.emc-enable-in
</code>

Your ssafety relay may look a bit different to this but here is mine

Rod,
I have a sole-person hobby shop running a simple conventional mill.
My judgment is that I don't need a sophisticated safety relay.

My arrangement has simple relays with:
 - a latching E-stop button that drops the E-stop relays,
    - the steppers are de-energized,
    - the spindle does a fast stop,
    - a signal is sent to I/O.

Re-start requires:
 - reset of the E-stop button,
 - initiate Machine On with either:
     - mouse select Machine On button on the Axis Command Line,
     - operate a Machine On push button on the operators control panel.

I haven't yet picked up on the subtle difference between the various Hal signals.
My solution uses 'halui .machine.on', you seemed to have used 'iocontrol.0.emc-enable-in'.
Are they different ? I will dig into the documentation.

John.
 

halui is exactly that. a hal ui so it has all the buttons a HMI panel needs.
iocontrol is about machine control (including estop)

I use the software estop, I have extensively tested it, and it hits the brakes on the spindle, and axis drives within 0.001 seconds of the button depression. I have a hydraulic power unit, which is controlled by the Axis machine on functions. So I need my machine to shut down and stop in a very specific way, and frankly, I don't trust estop wiring to work any better than a properly tested estop software feature. I used the IOcontrol pins