How to use 2 USRPs on 1 PC

I am testing RX TX example with 2 USRPs.

but now I have to just 1 PC.

When I connect 2 USRPs on 1 PC, my device list is like this:

ls -lR /dev/bus/usb

/dev/bus/usb/001:
total 0
crw-rw-r-- 1 root root 189, 0 2010-10-29 15:48 001
crw-rw---- 1 root usrp 189, 1 2010-10-29 15:59 002
crw-rw---- 1 root usrp 189, 2 2010-10-29 16:00 003

I just want to use one as a USRP sink and the other as a USRP source, in
GRC.

How can I solve this problem?

I know, 2 PC is better… but… :frowning: