The udev daemon is used by some Linux distributions to handle plug/unplug events for usb devices.

Follow these steps to allow users other than root to use the USRP:

1. Define a group named usrp.

 $ sudo addgroup usrp

2. Add users to it.

 $ sudo addgroup [username] usrp

For Fedora Core 5,6 and other distros without addgroup use (as root):

 # /usr/sbin/groupadd usrp

Add a user to the group

 # /usr/sbin/usermod -a usrp [username]

If your copy of usermod does not support this syntax (Redhat, Fedora) try

 # /usr/sbin/usermod -G usrp -a [username]

If your copy of usermod does not support this syntax (Suse) try

 # /usr/sbin/usermod -G usrp [username]

3. Create a file named /etc/udev/rules.d/10-usrp.rules with the following contents, and be sure to include the : in MODE:="0660" otherwise the default usb_device rule will override MODE to "0640". This also applies to the GROUP setting.

# rule to grant read/write access on USRP to group named usrp.
# to use, install this file in /etc/udev/rules.d as 10-usrp.rules
ACTION=="add", BUS=="usb", SYSFS{idVendor}=="fffe", SYSFS{idProduct}=="0002", GROUP:="usrp", MODE:="0660"

4. Restart the udev daemon to enable the changes.

$ sudo killall -HUP udevd

You can check if this is working by examining /dev/bus/usb after plugging in a USRP:

$ ls -lR /dev/bus/usb

You should see a device file with group usrp and mode crw-rw----