I have a LogiLink USB-To-Serial adapter. This has the PL2303 chip inside. When I insert the device: [26064.927083] usb 7-1: new full speed USB device using uhci_hcd and address 9 [26065.076090] usb 7-1: New USB device found, idVendor=067b, idProduct=2303 [26065.076099] usb 7-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [26065.076105] usb 7-1: Product: USB-Serial Controller [26065.076110] usb 7-1: Manufacturer: Prolific Technology Inc. [26065.079181] pl2303 7-1:1.0: pl2303 converter detected [26065.091296] usb 7-1: pl2303 converter now attached to ttyUSB0 So the device is recognized and the converter is attached to ttyUSB0. When I do screen /dev/ttyUSB0 9600 I get the error: bash: /dev/ttyUSB0: Permission denied So I went looking in the file permissions. ls -l from the /dev folder reports: crw-rw---- 1 root dialout 188, 0 2011-04-26 15:47 ttyUSB0 I added my user lars to the dialout group. When I use the commands groups under lars it shows that I'm in the group. Though I still recieve the permissions denied error, as lars, and as root. I'm trying to connect to a console cable to configure some Cisco switches. My OS is OpenSuse 11.3 x86_64 with kernel version 2.6.34.7-0.7-desktop.