How to identify multiple USB-serial adapters under Ubuntu 10.1

Question

I am reading data from multiple identical USB-serial adapters under Ubuntu 10.1.

On occasion, their /dev/tty path changes (eg if other USB devices are connected on s

Answer 1

I too was searching this topic for a way to find which physical USB device was assigned/connected to a logical /dev device name. So, after some trial and error, this is what worked best for me:

See what logical ttyUSBx devices exist (where x is 0, 1, 2...):

$ ls /dev

Show bus and device numbers for all usb-serial adapters:

$ lsusb 

Finally, use:

$ udevadm info --name=ttyUSBx --attribute-walk | grep num  

Now inspect the udevadm output to match the logical device name to the actual physical device. Here my listing when I did it:

$ lsusb
Bus 002 Device 005: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial     (UART) IC
Bus 002 Device 004: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Bus 002 Device 002: ID 80ee:0021  
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

$ udevadm info --name=ttyUSB0 --attribute-walk | grep num
    ATTRS{port_number}=="0"
    ATTRS{urbnum}=="812"
    ATTRS{busnum}=="2"
    ATTRS{devnum}=="5"
    ATTRS{urbnum}=="115"
    ATTRS{busnum}=="2"
    ATTRS{devnum}=="1"
    ATTRS{numa_node}=="-1"

$ udevadm info --name=ttyUSB1 --attribute-walk | grep num
    ATTRS{port_number}=="0"
    ATTRS{urbnum}=="465"
    ATTRS{busnum}=="2"
    ATTRS{devnum}=="4"
    ATTRS{urbnum}=="115"
    ATTRS{busnum}=="2"
    ATTRS{devnum}=="1"
    ATTRS{numa_node}=="-1"

So, in my case, ttyUSB0 is associated with the device on bus2, device5, which is the Future Technology Devices International USB to Serial Adapter; and likewise, ttyUSB1 is associated with the device on bus2, device4, which is the Prolific Technology, Inc. USB to Serial adapter.

And as has been pointed out, the command:

$ usb-devices

Will get you the same info in a one-line manner. I thought I'd post the details that helped me learn how the stuff worked behind the scenes...

Hope that was helpful :)