Since I can't do any printing at the moment (printer is broken), I have put together a bit of a tutorial on "best practice" when creating conditional G code.
There will be many far more qualified people than I on the forum to do this, and I'm sure that there is better and more concise documentation coming, but some may find it useful.
It is far from a complete or even comprehensive treatise on the subject, nor is it meant to be.
Feel free to correct, disagree or ignore as you see fit.
Especially since the code therein is untested (printer broken remember)
Conditional G Code best practice.pdf

just run a macro. (assuming you're running RRF3)
You could either do it manually or put it in the stop gcode of your slicer

;save_babystep.g
; Add babystep to Z offset and make "persistant"
if move.axes[2].babystep !=0
	echo {"Z trigger height altered by " ^ move.axes[2].babystep ^  "mm"}
	echo {"OLD: " ^ sensors.probes[0].triggerHeight ^ " new: " ^ sensors.probes[0].triggerHeight - move.axes[2].babystep}
	G31 Z{sensors.probes[0].triggerHeight - move.axes[2].babystep}
	M500 P10:31 ; save settings to config-overide.g - Must have M501 in config.g

else
	echo "No babystepping set.  Nothing to save"

EDIT: Original post incorrectly added baby steps to trigger height. It should subtract.

save_babystep.g

Hi All,
In my quest to tune my various settings I decided I needed to be able to automatically generate a test file that would change the pressure advance at set intervals.
The only programming language I know is Delphi/Lazarus, so I created a windows application to carry out the task.

Essentially that application creates a square box with two wall perimeters.
The inner wall prints at a constant speed and acts merely for support.
The outer wall alternates between a high and low speed with the transition point being mid way along the wall.
At the end of each layer a retraction is added.

This allows you to see how the PA adjustments are affecting corners at the two speeds and how it is affecting the retraction settings.

A start and end G code section takes care of temps etc.

Here are some pics of tests starting a PA of zero and increasing by 0.05 every 5mm in height.
My printer runs about a 350mm bowden tube.

Pic 1: PA range 0-0.35
Note the distinct thickness variations at the speed change point and the blobbing at the retraction/layer change point.

Pic2: PA Range 0.4-0.75
Transition line still faintly visible and some issues around retraction area

Pic3: PA range 0.8-1.15
Looks pretty good at about mid way

Pic4: PA range 1.2-1.55
Here we can see that pressure advance is starting to cause too much retraction.
I'd either have to reduce PA or try again with less retraction.

If anyone would like to try the application and provide feedback , I have put a link to my dropbox.

Download link:
https://www.dropbox.com/s/nolo5aca26e7fni/PaAdvanceTestInstall_v1-0.zip?dl=0

BE WARNED!!
This should be considered very much beta software.
Use at your own risk.
I've only tested on Windows 10.

I'm not sure my extrusion volume calculations are 100% accurate.
They seem close, but not identical to Cura's values.
At any rate it seems good enough for the test purposes.

This macro uses variables so needs RRF3.3b2 or later.

EDIT: Object model values for M558 are now stored in mm/min so no conversion necessary. - please used amended macro below which includes improvements and corrects some errors pointed out in this thread by other users.

It prompts you to jog the nozzle to the bed and then runs 10 probe offset tests (this number is configurable as a variable)
At the end, it discards the highest and lowest reading and averages the rest.
You can then choose to save the result in config-overide.g

;Calibrate BL Touch
; Reprap firmware version 3.3b2 or later required!

; if two speed probing is configured in M558,we probably want to reduce the speed for this test
var ProbeSpeedHigh = sensors.probes[0].speeds[0]*60 ; Speeds are saved in mm/sec in the object model but M558 uses mm/min
var ProbeSpeedLow = sensors.probes[0].speeds[1]*60


M558 F60 ; reduce probe speed to 60mm/min for accuracy - adjust F parameter as required

;define some variables to store readings

var NumTests=10 ; modify this value to define number of tests

; Do not change below this line
var RunningTotal=0
var Average=0
var Lowest=0
var Highest=0


; If the printer hasn't been homed, home it
if !move.axes[0].homed || !move.axes[1].homed || !move.axes[2].homed
  G28
else
	G1 Z{sensors.probes[0].diveHeight} F360 ; if axes homed move to dive height

M561 ; clear any bed transform

M290 R0 S0 ; clear babystepping

; move nozzle to centre of bed
G1 X{(move.axes[0].min + move.axes[0].max)/2} Y{(move.axes[1].min + move.axes[1].max)/2}

M564 S0 H0 ; Allow movement beyond limits

;ensure you have room for the probe
if move.axes[2].machinePosition < sensors.probes[0].diveHeight
	G1 Z{sensors.probes[0].diveHeight}
M280 P0 S160 I1 ; reset BL Touch
G4 S0.5
M98 P"0:/sys/retractprobe.g" ; Ensure probe is retracted & reset
G4 S0.5
M561 ; clear any bed transform
; Jog head to position
M291 P"Jog nozzle to touch bed" R"Set nozzle to zero" S3 Z1

G92 Z0 ; set Z position to zero
M291 P"Press OK to begin" R"Ready?" S3;

; Move probe over top of same point that nozzle was when zero was set
G1 Z{sensors.probes[0].diveHeight}; lift head
G1 X{move.axes[0].machinePosition - sensors.probes[0].offsets[0]} Y{move.axes[1].machinePosition - sensors.probes[0].offsets[1]} F1800

echo "Current probe offset = " ^ sensors.probes[0].triggerHeight ^ "mm"

; carry out 10 probes (or what is set in NumTests variable)

while iterations < var.NumTests
	G1 Z{sensors.probes[0].diveHeight} ; move to dive height
	if sensors.probes[0].value[0]=1000 ; if probe is in error state
		echo "Probe in error state- resetting"
		M280 P0 S160 I1 ; reset BL Touch
		G4 S0.5
		M98 P"0:/sys/retractprobe.g" ; Ensure probe is retracted & reset
		G4 S0.5
	G30 S-1
	M118 P2 S{"Test # " ^ (iterations+1) ^ " Triggered @ " ^ move.axes[2].machinePosition ^ "mm"} ; send trigger height to Paneldue console
	M118 P3 S{"Test # " ^ (iterations+1) ^ " Triggered @ " ^ move.axes[2].machinePosition ^ "mm"} ; send trigger height to DWC console

	if iterations == 0
		set var.Lowest={move.axes[2].machinePosition} ; set the new lowest reading to first probe height
		set var.Highest={move.axes[2].machinePosition} ; set the new highest reading to first probe height

	if move.axes[2].machinePosition < var.Lowest
		set var.Lowest={move.axes[2].machinePosition} ; set the new lowest reading
		;M118 P3 S{"new low reading = " ^ move.axes[2].machinePosition} ; send trigger height to DWC console
		G4 S0.3
	if move.axes[2].machinePosition > var.Highest
		set var.Highest={move.axes[2].machinePosition} ; set the new highest reading

		;M118 P3 S{"new high reading = " ^ move.axes[2].machinePosition} ; send trigger height to DWC console
		G4 S0.3
	set var.RunningTotal={var.RunningTotal + move.axes[2].machinePosition} ; set new running total
	;M118 P3 S{"running total = " ^ var.RunningTotal} ; send running total to DWC console
	G4 S0.5
set var.Average = {(var.RunningTotal - var.Highest - var.Lowest) / (var.NumTests - 2)} 	; calculate the average after discarding th ehigh & low reading

;M118 P3 S{"running total = " ^ var.RunningTotal} ; send running total to DWC console
;M118 P3 S{"low reading = " ^ var.Lowest} ; send low reading to DWC console
;M118 P3 S{"high reading = " ^ var.Highest} ; send high reading to DWC console
M118 P2 S{"Average excluding high and low reading = " ^ var.Average} ; send average to PanelDue console
M118 P3 S{"Average excluding high and low reading = " ^ var.Average} ; send average to DWC console

G31 P500 Z{var.Average} ; set Z probe offset to the average reading
M564 S0 H1 ; Reset limits
M558 F{var.ProbeSpeedHigh}:{var.ProbeSpeedLow} ; reset probe speed to original
G1 Z{sensors.probes[0].diveHeight} F360 ; move head back to dive height
M291 P{"Trigger height set to : " ^ sensors.probes[0].triggerHeight  ^ " OK to save to config-overide.g, cancel to use until next restart"} R"Finished" S3
M500 P31 ; optionally save result to config-overide.g

@Tinchus
Political correctness has spread even to RRF.
In the spirit of inclusiveness , you must now use "processing" in deference to those machines that do not identify as "printers"

Recently I had to set up a Raspberry Pi is camera to use as a monitoring device for my printer.
I found that pretty much all the online information was outdated and had no end trouble getting it to work on the current version of Pi OS (Bullseye Bookworm).
The entire camera and video handling system has changed over the years.
So I decided to document what worked for me.
In the end it was relatively easy (once you knew the correct steps0

I must first point out I know bugger all about Linux.
All this work is taken from bits and pieces I found on various sites and cobbled together, so my apologies for not crediting the original author(s)

NOTE: These instructions were done using a Raspberry Pi 4 running Bullseye Bookworm 64 bit and an official Pi camera
Also if you're running RRF in SBC mode, you don't need to do this as I believe it has a built in camera setup.

The first step is to install the OS using the Pi Imager
https://www.raspberrypi.com/software/

When prompted, choose your user name, password and Wifi details.
NOTE: The current version no longer uses the default user pi and password raspberry

when you get to this point, click on "edit settings"

Enable SSH so that you can connect to the Pi via PUTTY rather than always needing a monitor and keyboard.
If you installed a Pi OS that has a desktop you can use the inbuilt command line terminal for all the steps listed below.

Then click on YES to apply the settings.

Once the image has been loaded onto the SD card, insert the card in your Pi and start it up.

Start Putty (or some other terminal) and SSH into the Pi
If you used the default settings, you should be able to go to
raspberrypi.local

You should see something like this

You may get any updates/upgrade by using these commands

sudo apt update

sudo apt upgrade

sudo apt install

Change directory

cd /usr/local/bin/

Open a text edior

sudo nano streamVideo.py

Paste in the following code

#!/usr/bin/python3

# This is the same as mjpeg_server.py, but uses the h/w MJPEG encoder.

import io
import logging
import socketserver
from http import server
from threading import Condition

from picamera2 import Picamera2
from picamera2.encoders import MJPEGEncoder
from picamera2.outputs import FileOutput

PAGE = """\
<html>
<head>
<title>3D Printer Camera</title>
</head>
<body>
<img src="stream.mjpg" width="800" height="600" />
</body>
</html>
"""


class StreamingOutput(io.BufferedIOBase):
    def __init__(self):
        self.frame = None
        self.condition = Condition()

    def write(self, buf):
        with self.condition:
            self.frame = buf
            self.condition.notify_all()


class StreamingHandler(server.BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == '/':
            self.send_response(301)
            self.send_header('Location', '/index.html')
            self.end_headers()
        elif self.path == '/index.html':
            content = PAGE.encode('utf-8')
            self.send_response(200)
            self.send_header('Content-Type', 'text/html')
            self.send_header('Content-Length', len(content))
            self.end_headers()
            self.wfile.write(content)
        elif self.path == '/stream.mjpg':
            self.send_response(200)
            self.send_header('Age', 0)
            self.send_header('Cache-Control', 'no-cache, private')
            self.send_header('Pragma', 'no-cache')
            self.send_header('Content-Type', 'multipart/x-mixed-replace; boundary=FRAME')
            self.end_headers()
            try:
                while True:
                    with output.condition:
                        output.condition.wait()
                        frame = output.frame
                    self.wfile.write(b'--FRAME\r\n')
                    self.send_header('Content-Type', 'image/jpeg')
                    self.send_header('Content-Length', len(frame))
                    self.end_headers()
                    self.wfile.write(frame)
                    self.wfile.write(b'\r\n')
            except Exception as e:
                logging.warning(
                    'Removed streaming client %s: %s',
                    self.client_address, str(e))
        else:
            self.send_error(404)
            self.end_headers()


class StreamingServer(socketserver.ThreadingMixIn, server.HTTPServer):
    allow_reuse_address = True
    daemon_threads = True


picam2 = Picamera2()
picam2.configure(picam2.create_video_configuration(main={"size": (640, 480)}))
output = StreamingOutput()
picam2.start_recording(MJPEGEncoder(), FileOutput(output))

try:
    address = ('', 8888)
    server = StreamingServer(address, StreamingHandler)
    server.serve_forever()
finally:
    picam2.stop_recording()

Press CTRL + X to exit and choose Y to save file

change directory

cd /etc/systemd/system

Open the text editor to create a system service file

sudo nano streamVideo.service

Paste in the following code

[Unit]
Description=A script for straming video to http
After=syslog.target network.target

[Service]
WorkingDirectory=/usr/local/bin/
ExecStart=/usr/bin/python3 /usr/local/bin/streamVideo.py

Restart=always
RestartSec=120

[Install]
WantedBy=multi-user.target

PRess CTRL + X
press Y and enter to save

Enter the following to reload the daemon

sudo systemctl daemon-reload

Enable the service

sudo systemctl enable streamVideo.service

You should see something like
Created symlink /etc/systemd/system/multi-user.target.wants/streamVideo.service → /etc/systemd/system/streamVideo.service.

Restart the Pi

sudo shutdown -r now

After the Pi has rebooted, you should be able to access the stream by going to the following URL in your browser

http://raspberrypi.local:8888/index.html

In DWC you need to enter this URL on order to get the stream

http://raspberrypi.local:8888/stream.mjpg

Your video stream should now be visible in the Webcam tab

I hope this saves someone some frustration.

I have updated the syntax file for RJ TextEd to include more object model items.
I have also included a suggested colour format file.
You will need to update RJ TextEd to the latest version in order to take advantage of hints etc.

Download here

Replace the existing files (reprap.syx, reprap.ini) in C:\Users"yourname"\AppData\Roaming\RJ TextEd\Syntax
Copy the file "Reprap Dark.xml" to C:\Users"yourname"\AppData\Roaming\RJ TextEd\Syntax color themes\

To install.
1: Go to ENVIRONMENT > THEMES > CUSTOMISE

2: Select "Reprap G Code" from the drop down list of highlighters

3: Click the button, and select import colors from file

4: Select the "Reprap Dark.xml" file previously copied.

You can customize the colours to suit yourself.
Different G Code parameters such as X, Y, Z , E, F, G etc can be coloured to make individually.
Likewise, comments and other items can be individually coloured.

Now that 3.1 is released, I think it would be beneficial to have a forum category dedicated to conditional gcode & macros.
This should probably be broken down into various kinematic types.
Furthermore it may be good to have some sort of “duet approved” marker like the “solved” marker, once the macros have been peer reviewed and improved where necessary.
I usually try to make macros “portable” by not hard coding anything, but the very fact that certain parts of the object model are not visible if you don’t run that type of configuration, probably makes putting them in the categories for which they were designed beneficial and will reduce angst and support time.
(Yes, I know we should be checking for null objects and kinematic types as a matter of course in every macro)
Which leads to my final point, which is once we have some documentation on the object model, perhaps someone could do a small tutorial on best practice when writing macros.
My programming background is not in C or its variants so I admit I’m constantly searching for proper syntax etc.
To a non-programmer it is just gobbledygook.
If there’s going to be dozens of people learning to do it, they may as well learn to do it in a way that ensure portability and reduces the chance of unexpected issues.
I’ve always found it usually takes 10 lines of code to do the job, the another 50 lines of code to stop people trying to do it out of order or in a way you never imagined

I found another application that works quite easily and has the benefit of being able to adjust all the settings from the web interface.

It's called picamera2-WebUI-Lite

There's a slight error on the instructions to install and it doesn't tell you how to set it up as a service, so I've listed thesteps.

To install.

SSH into your PI (or open a terminal if using a desktop)

Change directory

cd /usr/local/bin/

Clone the repositry

 sudo git clone https://github.com/monkeymademe/picamera2-WebUI-Lite.git

Change directory

cd /usr/local/bin/picamera2-WebUI-Lite 

Test that it's running

 python3 app.py 

Open your browser and go to
http://raspberrypi.local:8080/

To see just the video feed go to
http://raspberrypi.local:8080/video_feed

Go back to the terminal and hot CTRL + C to shut the app down

To set it up as a service
Change directory

cd /etc/systemd/system

Open a text editor to create a system service file

sudo nano webui-lite.service

Paste in the following

[Unit]
Description=Start script for WebUi-Lite as a service
After=syslog.target network.target
[Service]
WorkingDirectory=/usr/local/bin/picamera2-WebUI-Lite/
ExecStart=/usr/bin/python3 /usr/local/bin//picamera2-WebUI-Lite/app.py
Restart=always
RestartSec=120
[Install]
WantedBy=multi-user.target

Press CTRL + X to exit and Y to save

Reload the daemon

sudo systemctl daemon-reload

Enable the service

sudo systemctl enable webui-lite.service

NOTE that if you already have the other streamVideo service I listed above using Picamera you will have to disable it as you can't run both.

sudo systemctl disable streamVideo.service

Reboot the system to make sure the service starts

sudo shutdown -r now

Adjust your DWC settings as follows

This will allow you to easily get to the settings page by clicking on the webcam image in DWC
From there adjust your resolution and you can also zoom in a particular area using the scaler crop settings.

Full view

Cropped view

For those using RJ Text Editor, I have posted an updated syntax file that includes the new object model items and G Codes contained in RRF3.5.0 b2

It can be downloaded here
https://www.rj-texted.se/Forum/viewtopic.php?p=18659#p18659

It includes mouse over hints for G Code commands and auto-complete
The program comes with the RRF syntax file as standard but you may need to update it as new firmware versions come out.

@SonnyD1
I'm afraid I know nothing about scanning probes, so I'll leave that for someone else

@SonnyD1

You have M557 commented out in your config so I'm guessing it's (the probe grid) undefined when you access the object model variables in your home.z

; Mesh Bed Compensation
;M557 X25:175 Y25:175 S40:40                                     ; define grid for mesh bed compensation

Try echoing the variable positions to confirm

; home Z
var xCenter = move.compensation.probeGrid.mins[0] + (move.compensation.probeGrid.maxs[0] - move.compensation.probeGrid.mins[0]) / 2 - sensors.probes[0].offsets[0]
var yCenter = move.compensation.probeGrid.mins[1] + (move.compensation.probeGrid.maxs[1] - move.compensation.probeGrid.mins[1]) / 2 - sensors.probes[0].offsets[1]

echo "x position " , var.Center
echo "y position " , var.yCenter

G1 X{var.xCenter} Y{var.yCenter} F6000 ; go to bed centre
M558 F4000:150

@dc42 said in metacode rread-only variables:

@OwenD using 'const' wouldn't affect the memory usage.

Ah well.
In that case I can dress in either direction.
Can't hurt anyone and may help some.

@dc42 said in metacode rread-only variables:

maybe "global const" could create a global constant and "const" by itself create a local constant.

This is probably closest to convention with most languages.
If it resulted in lower memory usage then I'd vote for it.

@Surgikill said in Triggering 'Load Filament' prompt with a macro:

@dc42 Yes, I am doing that now. However, I want the prompt to contain options that are dynamically created based on the content of "0:/filaments". I don't want to update the prompt every time I add a filament, or modify the name of a filament. Just like how DWC creates the prompt when pressing the 'Load Filament' button.

At present RRF doesn't have any string handling routines and no way of extracting file information or file lists.
The best you can do is use the object model item
move.extruders[0].filament
which will show the currently loaded filament (or null)
I ran into a similar issue trying to create a filament change macro to use from PanelDue as my printer is in the shed and my computer inside.
I had to manually list all the filament types I use in an array.

This is what I came up with.
It may (or may not) help in your case.

; ChangeFilament.g
; requires RRF 3.5 or later!

; list of filaments must follow rules for array
; https://docs.duet3d.com/User_manual/Reference/Gcode_meta_commands#array-expressions

var filaments = {"ABS","ABS-CF","ABS-GF","ASA","EDGE","eFlex","eLastic","FLEX","HIPS","NGEN","NYLON","PA-CF","PC","PCABS","PDVF","PEEK","PEI","PEKK","PET","PETG","PLA","POM","PP","PSU","PVA","SCAFF","TPE","TPU",} ; list your filaments here
var maxBtns = 10;  Max number of buttons per page on PanelDue.  Adjust as required.  5 works OK on 7"paneldue - 9 is max!

; don't change below here

var thisTool = state.currentTool

var allTools = vector(#tools,null)


if var.thisTool = -1
	if #tools > 1
		while iterations < #tools
			set var.allTools[iterations] =  tools[iterations].name ^ ""
		M291 S4 P"Select tool" K{var.allTools} F0
		T{input}
		G4 S1
		if state.currentTool = -1
			abort "No tool selected"
		else
			set var.thisTool = state.currentTool
	else
	T1
var thisExtruder = 0
var allExtruders = vector(#tools[var.thisTool].extruders,null)
if #tools[var.thisTool].extruders > 1
	
	while iterations < #tools[var.thisTool].extruders
		set var.allExtruders[iterations] = iterations ^ ""
	M291 P"Select extruder" S4 K{var.allExtruders} F0
	set var.thisExtruder = input
			
var thisFilament = move.extruders[tools[var.thisTool].extruders[var.thisExtruder]].filament
var newFilament = null
if var.maxBtns > 10
	set var.maxBtns = 10
	echo "Paneldue can only display 10 buttons in total"
	echo "Max buttons has been reset"
var thisPage = vector(var.maxBtns,"") 
var numPages = floor(#var.filaments / (var.maxBtns - 1))
if mod(#var.filaments , var.maxBtns - 1) > 0
	set var.numPages = var.numPages + 1
var pagesDone = 0;
var btnsDone = 0
var nextFilament = ""
var nextItem = 0
while var.pagesDone < var.numPages 
	set var.thisPage = vector(var.maxBtns,"")
	set var.btnsDone = 0 
	while var.btnsDone < var.maxBtns-1
		set var.nextItem = iterations + (var.pagesDone * (var.maxBtns-1))
		if var.nextItem = #var.filaments
			break
		set var.thisPage[var.btnsDone] = var.filaments[var.nextItem]
		set var.nextFilament =  var.filaments[var.nextItem]
		set var.btnsDone = var.btnsDone + 1		
	if var.pagesDone = var.numPages - 1
		set var.thisPage[{var.maxBtns-1}] = "Cancel"
	else
		set var.thisPage[{var.maxBtns-1}] = "Next"
	set var.pagesDone = var.pagesDone + 1
	M291 P"Select filament" S4 K{var.thisPage}
	if input = var.maxBtns-1
		continue 
	else
		set var.newFilament = var.thisPage[input]
		break
if (var.newFilament = null) || (var.newFilament = "")
	abort "No filaments chosen"
else
	echo "Filament chosen : ", var.newFilament, " : commence change"
	
; M701 only works if the tool only has one extruder
; If more than one extruder is present on the tool, we'll directly call the macros for load, unload and config
; It's unclear if the filament will be marked as loaded in DWC after this approach.

if var.newFilament = "noFilament"
		if #tools[var.thisTool].extruders > 1   
			M98 P{directories.filaments ^ var.newFilament ^ "/load.g"}  S{var.thisExtruder}
			M98 P{directories.filaments ^ var.newFilament ^ "/config.g"}  S{var.thisExtruder}	
		else
			M701 S{var.newFilament}
			if result != 0 
				abort "Error during loading"
			M703	
else
	if (var.thisFilament != "noFilament") && (var.thisFilament != null)
		
		if #tools[var.thisTool].extruders > 1   ; M701 only works if the too only has one extruder
			M98 P{directories.filaments ^ var.newFilament ^ "/unload.g"}  S{var.thisExtruder}
			M98 P{directories.filaments ^ var.newFilament ^ "/load.g"}  S{var.thisExtruder}
			M98 P{directories.filaments ^ var.newFilament ^ "/config.g"}  S{var.thisExtruder}	
		else
			M702
			M701 S{var.newFilament}
			if result != 0 
				abort "Error during loading"
			M703
	

@Tinchus

From the docs..,
The H parameter defines the Z probe dive height, which is the height above the trigger height from which probing starts. The default is 3mm or 5mm depending on firmware version. You may wish to increase it during initial calibration. When using mesh bed compensation or running G30 commands with specified XY coordinates (for example from the bed.g file), the firmware moves the Z probe to this height above where it expects the bed to be before commencing probing. The maximum depth of probing from this position is twice the dive height.

I think you'll find on straight G30 Z home, the dive height is ignored as the height is unknown.
Otherwise you would never be able to home from any height.
About the best you can do is check for typical errors before you start using the object model.

I use this macro which is called before any Z homing or bed leveling

check BL Touch
var probeOK = true
if sensors.probes[0].value[0]=1000 ; if probe is in error state
	set var.probeOK = false
	echo "Probe in error state- resetting"
	M280 P0 S160 ; reset BL Touch
	G4 S0.5
if state.gpOut[0].pwm < 0.05
	set var.probeOK = false
	echo "Probe is already deployed - retracting"
	M98 P"0:/sys/retractprobe.g"
	G4 S0.5

if sensors.endstops[2].triggered
	set var.probeOK = false
	echo "Probe is already triggered - resetting"
	M280 P0 S160 ; reset BL Touch
	G4 S0.5

I also use this check in my homeall.g to cancel the print if any errors occur during homing
Any successful command should return a value of 0

G30               ; home Z by probing the bed
if result !=0
	abort "Print cancelled due to probe error"

Outside that, you'd have to have a secondary switch, pressure sensor or similar attached I'd think.

@dc42
I have attached the config.g and the other macros called.
Also the filament config.g as that is where I am setting pressure advance if that's relevant.

config(ABS).g
set_max_speeds.g
config.g
setInputShaping.g
config-override.g
daemon.g

@curieos
I've found that if you have much going on in daemon.g the any "songs" will be very erratic in behaviour.
I have a variable at the start of daemon.g which allows me to temporarily skip it, which helps, but doesn't make it perfect.
I suspect there's so much going on in the firmware now that's taking up cycles that M300 will not be useful for much more than single tones.

Just had this error occur again.
It's not 100% repeatable as I've had it fail twice on the same print (with two firmware versions) but print successfully the next try.
Both failures were 5-6 hours into the print.

M122
=== Diagnostics ===
RepRapFirmware for Duet 2 WiFi/Ethernet version 3.6.0-beta.1 (2024-09-24 10:07:04) running on Duet WiFi 1.02 or later
Board ID: 08DGM-917NK-F2MS4-7J1DA-3S86T-TZTWD
Used output buffers: 10 of 26 (26 max)
=== RTOS ===
Static ram: 23360
Dynamic ram: 71876 of which 12 recycled
Never used RAM 8860, free system stack 100 words
Tasks: NETWORK(2,nWait 6,15.7%,181) ACCEL(6,nWait 5,0.0%,345) HEAT(3,nWait 5,0.1%,307) Move(4,invalid,3.6%,266) MAIN(1,running,80.1%,630) IDLE(0,ready,0.5%,29), total 100.0%
Owned mutexes: WiFi(NETWORK)
=== Platform ===
Last reset 09:14:16 ago, cause: software
Last software reset at 2024-09-22 17:49, reason: User, Gcodes spinning, available RAM 22200, slot 2
Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x00400000 BFAR 0xe000ed38 SP 0x00000000 Task MAIN Freestk 0 n/a
Error status: 0x1c
Aux0 errors 0,0,0
MCU temperature: min 19.6, current 26.3, max 26.7
Supply voltage: min 0.4, current 24.2, max 24.5, under voltage events: 0, over voltage events: 0, power good: yes
Heap OK, handles allocated/used 99/22, heap memory allocated/used/recyclable 2048/596/212, gc cycles 945
Events: 0 queued, 0 completed
Date/time: 2024-09-28 16:07:45
Slowest loop: 1122.06ms; fastest: 0.10ms
I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0
=== Storage ===
Free file entries: 8
SD card 0 detected, interface speed: 20.0MBytes/sec
SD card longest read time 13.0ms, write time 417.1ms, max retries 0
=== Move ===
Segments created 582, maxWait 3825401ms, bed comp in use: mesh, height map offset 0.000, hiccups added 0 (0.00ms), max steps late 1, ebfmin 0.00, ebfmax 0.00
Pos req/act/dcf: 8937.00/8893/0.97 7099.00/7144/-0.16 48408.00/48408/0.00
no step interrupt scheduled
Driver 0: standstill, SG min n/a
Driver 1: standstill, SG min 201
Driver 2: standstill, SG min 0
Driver 3: standstill, SG min 0
Driver 4: standstill, SG min 228
Driver 5: 
Driver 6: 
Driver 7: 
Driver 8: 
Driver 9: 
Driver 10: 
Driver 11: 
=== DDARing 0 ===
Scheduled moves 2520037, completed 2520035, LaErrors 0, Underruns [21, 0, 0]
=== Heat ===
Bed heaters 0 -1 -1 -1, chamber heaters -1 -1 -1 -1, ordering errs 0
Heater 0 is on, I-accum = 0.3
Heater 1 is on, I-accum = 0.3
=== GCodes ===
Movement locks held by null
HTTP is idle in state(s) 0
Telnet is idle in state(s) 0
File is idle in state(s) 3
USB is idle in state(s) 0
Aux is idle in state(s) 0
Trigger is idle in state(s) 0
Queue is idle in state(s) 0
LCD is idle in state(s) 0
Daemon is doing "G4 S2" in state(s) 0 0, running macro
Autopause is idle in state(s) 0
Q0 segments left 9
Code queue 0 is empty
=== Filament sensors ===
check 107327487 clear 16019414
Extruder 0 sensor: ok
=== Network ===
Slowest loop: 1253.54ms; fastest: 0.00ms
Responder states: HTTP(0) HTTP(4) HTTP(0) FTP(0) Telnet(0)
HTTP sessions: 1 of 8
=== WiFi ===
Interface state: active
Module is connected to access point 
Failed messages: pending 0, notrdy 0, noresp 0
Firmware version 2.1.0
MAC address bc:dd:c2:89:a0:bb
Module reset reason: Power up, Vcc 3.38, flash size 4194304, free heap 40588
WiFi IP address 192.168.1.163
Signal strength -41dBm, channel 6, mode 802.11n, reconnections 0
Clock register 00002002
Socket states: 0 0 0 0 0 0 0 0

EDIT
One difference this time is that when I shut the power off, no resurrect.g was created, so it looks like I've lost this print.

Now the print is finished I have just tested sending G94 from the command line and it gives no errors, so I've answered that half of the question.