Modbus RTU serial port
From Proview Wiki
In order to use a serial port, (pwrp) user must be a part of dialout group
The port device (name) may be /dev/ttyS0 (for a pci card) or /dev/ttyMI0 (Moxa card) or /dev/ttyUSB0 (usb/serial converter)
chmod 0777 /dev/ttyS0
chmod a+rw /dev/usb/002/003
ls -l /dev/ttyS0
lsusb
dmesg | grep tty
