IC-735 CAT control in Linux

I use a home made CAT interface using FTDI USB to TTL serial device.
In linux USB enumeration seems unpredictable so what was /dev/ttyUSB0 last time could be /dev/ttyUSB2 the next boot. This can be resolved by adding a udev rule. Create a file called 97-usb-serial.rules in /etc/udev/rules.d
This askUbuntu article explains.

In my case this is the file:
SUBSYSTEM==”tty”, ATTRS{idVendor}==”0403″, ATTRS{idProduct}==”6001″, ATTRS{serial}==”A600c0BY”, SYMLINK+=”ttyIC735″, GROUP=”dialout”

Unfortunately the  cheap and reliable CH340 USB -sertial TTL chip used in many Arduino clones and cheap interface cards does not have a unique serial number in each chip.