Install GNU Radio Companion and the latest UHD.

apt install gnuradio uhd-host
uhd_images_downloader

USB connect the USRP B200/B210 and type

uhd_find_devices

You will see feedback including:

-- Loading firmware image: /usr/share/uhd/images/usrp_b200_fw.hex...
done

-- UHD Device 0

Device Address:
type: b200
name:
serial: XXXXX
product: B200

Here are several simple and fun GNU Radio examples for the Ettus B200

Troubleshooting:

thread[thread-per-block[3]: <block gr uhd usrp source (1)>]: EnvironmentError: IOError: Radio ctrl (0) packet parse error - AssertionError: packet_info.packet_count == (seq_to_ack & 0xfff)
  in uint64_t radio_ctrl_core_3000_impl::wait_for_ack(bool)
  at /build/uhd-fDtHan/uhd-3.9.2/host/lib/usrp/cores/radio_ctrl_core_3000.cpp:264

This error can indicate there is an excessive dataflow rate. Try reducing your sample rate. Check if you’re connected via USB 3 and not USB 2 (is USB Type A all the way into your computer USB 3 jack?) Check via:

dmesg

You should see

new SuperSpeed USB device number 3 using xhci_hcd
LPM exit latency is zeroed, disabling LPM.
New USB device found, idVendor=2500, idProduct=0020
New USB device strings: Mfr=1, Product=2, SerialNumber=3
Product: USRP B200
Manufacturer: Ettus Research LLC