Read the S-Command in the HAL

Start
Prev
1
Next
End

Wiesi-94
Offline
New Member

28 Mar 2025 20:05 #325187 by Wiesi-94

Read the S-Command in the HAL was created by Wiesi-94

Hello,
I'm currently implementing a retrofit for our SHW UF31. So far, progress is pretty good. But I have a small problem with the gear selection.
I'm using Classic Ladder to shift the three gears. It works quite well so far. I have a float input for the spindle speed, which is used to select and engage the correct gear.

The plan is to use the S command to set the gear. But I don't know which HAL pin I can use to query the set speed without the spindle running.

So what I need is a way to read this system parameter in the HAL / Classic Ladder:
#<_rpm> - Return the current value of S, not the actual spindle speed.

Best regards, Stefan

Please Log in or Create an account to join the conversation.

cmorley
Offline
Moderator

29 Mar 2025 05:11 #325225 by cmorley

Replied by cmorley on topic Read the S-Command in the HAL

you could try something this:
linuxcnc.org/docs/devel/html/gui/gstat.h...mponent_code_pattern

but use the message 's-code-changed'

Please Log in or Create an account to join the conversation.

Wiesi-94
Offline
New Member

31 Mar 2025 16:35 #325411 by Wiesi-94

Replied by Wiesi-94 on topic Read the S-Command in the HAL

That works, thanks!!

The following user(s) said Thank You: cmorley

Please Log in or Create an account to join the conversation.

Doc_emmet
Offline
New Member

21 May 2025 22:28 #328879 by Doc_emmet

Replied by Doc_emmet on topic Read the S-Command in the HAL

Hello, can you show me how to read the S command and what you changed.

Please Log in or Create an account to join the conversation.

Todd Zuercher
Offline
Platinum Member

22 May 2025 11:26 #328906 by Todd Zuercher

Replied by Todd Zuercher on topic Read the S-Command in the HAL

To do the above suggestion to get a hal pin that shows the commanded S speed even when the spindle is stopped. The link gives instructions for creating a python script that reads what the commanded S speed settinging is from the Gstat python module and then creates a hal pin and writes the value to it.

You will need to create at python script with the following, and save it as a file in your config directory named "spindle.py" and make that file executable.

#!/usr/bin/env python3

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import GObject
from gi.repository import GLib
import hal
from hal_glib import GStat
GSTAT = GStat()

# callback to change HAL pin state
def mode_changed(obj, data):
        h['speed'] = data

# Make a component and pins
h = hal.component("spindle_setting")
h.newpin("speed", hal.HAL_FLOAT, hal.HAL_OUT)
h.ready()

# connect a GSTAT message to a callback function
GSTAT.connect("s-code-changed",mode_changed)

# force GSTAT to initialize states
GSTAT.forced_update()

# loop till exit
try:
    GLib.MainLoop().run()
except KeyboardInterrupt:
    raise SystemExit

Then load/run that python script when you start Linuxcnc by adding this line to your hal file for your config. (Replacing YOUR_CONFIG with the name of your config dir.)

loadusr python3 ~/linuxcnc/configs/YOUR_CONFIG/spindle.py

You can even test this before adding it to your hal file by simply running the python script from command line while Linuxcnc is running. Just type "python3 ~/linuxcnc/configs/YOUR_CONFIG/spindle.py" and hit enter. (After first creating the spindle.py file, saving it to your config dir.)

The following user(s) said Thank You: Benb

Please Log in or Create an account to join the conversation.

Doc_emmet
Offline
New Member

22 May 2025 22:01 #328946 by Doc_emmet

Replied by Doc_emmet on topic Read the S-Command in the HAL

Thanks, it works

Please Log in or Create an account to join the conversation.

Start
Prev
1
Next
End

Time to create page: 0.116 seconds