hey there,
the problem is within the knx binding rasp pi2 and raspbian jessie:
it says :“knx interface wether /dev/ttys0 or /dev/ttyUSB0” but none of those exist. I only got /dev/AMA0, but that doesn’t seem to work.
knx:serialPort=/dev/ttyAMA0
ls -la /dev/tty* shows a lot of fancy tty’s, but no usb 
do I need to install eibd? I hope not, the manual says that the knx binding does the job.
any suggestions?
uh, seems like noone uses usb to knx binding… o.k. lets ask another way: the rasp pi2 has 4 usb ports, is that the reason why i can’t connect via ttyusb0?
any help appreciated. can i skrew something up with installing eibd-daemon only to test, if this helps?
two hours later… I found out that ttyama0 is the serial connector on top of the pi. that means the pi refuses to have usb ports >_< but i can clearly see four of them on the side of the pcb… but no /dev/ttyUSB* to see in linux. funny, cause all four ports are in use, and work.
…again some hours later…
The Rasp recognizes the interface now, as dmesg shows:
[ 2.854593] usb 1-1.4: Manufacturer: ABB STOTZ-KONTAKT GmbH
[ 2.861745] systemd[1]: Mounting FUSE Control File System…
[ 2.870341] hid-generic 0003:147B:5120.0003: hiddev0,hidraw2: USB HID v1.01 Device [ABB STOTZ-KONTAKT GmbH KNX-USB Interface (MDRC)] on usb-3f980000.usb-1.4/input0
but it thinks the interface is an HID, which results in a mount at /dev/hidraw2 rather than ttyUSB. great.
My head aches now, and there’s a little smoke coming out of my ears… good n8
Mkay, now I figured out how to set an uvdev rule to get the ttyS0 file.
The file looks like this now:
pi@raspberrypi:~ $ ls -l /dev/ttyS0
lrwxrwxrwx 1 root root 15 Mär 6 10:48 /dev/ttyS0 -> bus/usb/001/009
Links this file:
pi@raspberrypi:~ $ ls -l /dev/bus/usb/001/009
crw-rw-r-- 1 root eibd 189, 8 Mär 6 10:48 /dev/bus/usb/001/009
This now means to me: Everybody can use the ttyS0 file. root or eibd can use the usb device, right?
Which user or usergroup is openhab? B’cause I still can’t send or receive telegrams with the USB device
Supplemental: If I unplug/plug the USB/S1.1 the files do exactly as expected 
so that’s kinda huge leap for me.
Hi I’ve the same problem and the same configuration (Raspberry PI 2 + ABB) but…
I can’t find my USB device…
Could you help me?
Hi, could you post me your “openhab.config” file??
Guys any updates?
plan to use USB KNX gateway,
Does KNX binding allows to work with USB-KNX gateway in the same way as with Ethernet-KNX gateway?