To connect the Power Meter to a Linux box, one needs to convert the RS-485 Bus Protocol to an USB Protocol using an RS-485 to USB Converter.
To generate a unique device id for the USB port of the RS-485 to USB converter we have to define it's vendor and product id in the definition files for the udev daemon:
cd /etc/udev/rules.d
sudo nano 50-usb.rules
enter the following line into the editor
SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", SYMLINK+="ORNO", MODE="0666"
where the vendor id and the product id are the ones of the above mentioned converter. If you use a different product you'll need to inspect the output of
dmesg
to identify which USB port the converter has been connected to and then
lsusb
to get the vendor and product id of the respective device at this port. After reboot the new symlink
/dev/ORNO
has been created which is the default port the script is accessing.
Alternatively to a reboot one can issue
sudo udevadm control --reload-rules && sudo udevadm trigger
According to this forum if the rule does not work one needs to uninstall the Braille tty driver with
sudo apt remove brltty
then the named port ORNO should be linked correctly to a ttyUSBx port.