Problem connecting hy_vfd via RS485

I am setting up a cnc mill and connected it to Linuxcnc. I found solutions to all my Problems here in the forum,
but now I'm stuck.
Yesterday I tried to connect my vfd to an RS485USB Dongle and I could start the spindle with these commands

sudo chown 666 /dev/ttyUSB0
halrun
loadusr -Wn hy_vfd hy_vfd -n hy_vfd -d /dev/ttyUSB0 -p none -r 19200 -s 1
show pin
setp hy_vfd.enable 1
setp hy_vfd.speed-command 12000
setp hy_vfd.spindle-forward 1
setp hy_vfd.spindle-on 1

I put in some commands in my hal file to start the spindle, but it didn't want to do a single turn.
I thought that I didn't have enough rights and copied the config files to the root account and
started the spindle via the above halrun commands with root rights and it worked, but linuxnc didn't start with a
"Refusing to run as root without fallback UID specified". So I logged back into my user account trying to
start the spindle again via halrun, but now it even starts there, giving back a:

open: Permission denied
ERROR Can't open the device /dev/ttyUSB0 (errno 13)
hy_vfd: ERROR: couldn't open serial device
<stdin>:3: waitpid failed hy_vfd hy_vfd
<stdin>:3: hy_vfd exited without becoming ready
halcmd: Note: Using POSIX realtime

a su does turn the spindle.

Linuxcnc doesn't start anymore, the serial /dev/ttyUSB0 could not be opened.
I would really appreciate it if somebody could give me a hint.
Thanks

That was quick and it worked as the halrun is concerned, thanks a lot.
Still the problem that the spindle doesn't turn in the linuxcnc Gui.

Do you have made a udev rule for the USB device? Can halp but must not.

It seems the dialout group was the Problem. Now I can start at least the spindle.
It still doesn't react to M3 or M5, but I think I have to configure that in the hal file.

Now the spindle is working almost as I wish.
There is still one thing I didn't find out.
The speed goes from 11520 reverse to 11520 forward.
Is there a possibility to go to 24000? I think the Huanyang spindle can
do that.
The manual is quite technical for a non-engineer...

Here they are