USRP N320/321 LO sharing issues

[Seydouba Fofana]

Hello everyone,

I am setting up a MIMO system with usrp N320 and N321, as you can imagine I am facing some problems.

The first one is  relative to USRP module synchronization, especially about LO distribution through Usrp N321 . To allow you understand I have attached test files  grc and python, where you will find uhd_source/sink block configuration. I settled those blocks as recommended but I get nothing on the USRP N321 Tx LO output, therefore nothing on the supposed synchronized USRP devices RF output.

Then , secondly, I often get an error at the launching phase saying that one of the IP addresses I am using is claimed by another device. It happened when I used the MIMO setting for UHD_Sink and UHD_Source in the same flowgraph at the same time. That problem never happens, when I only use one of those 2 blocks. Bellow is the error message:

Generating: '/home/oln-ant/Documents/Full_Com_Example/Transceiver_Cal_Unit/Test_grc.py'
Executing: /usr/bin/python3.6 -u /home/oln-ant/Documents/Full_Com_Example/Transceiver_Cal_Unit/Test_grc.py

[INFO] [UHD] linux; GNU C++ version 6.5.0 20181026; Boost_106501; UHD_4.0.0.HEAD-0-g90ce6062
[INFO] [MPMD] Initializing 2 device(s) in parallel with args: mgmt_addr0=192.168.11.2,type0=n3xx,product0=n320,serial0=31DB241,claimed0=False,mgmt_addr1=192.168.10.2,type1=n3xx,product1=n320,serial1=31F43BD,claimed1=False,addr0=192.168.11.2,addr1=192.168.10.2,type=n3xx,master_clock_rate=245.76e6
[WARNING] [MPM.RPCServer] A timeout event occured!
[WARNING] [MPM.RPCServer] A timeout event occured!
[INFO] [MPM.PeriphManager] init() called with device args `master_clock_rate=245.76e6,mgmt_addr=192.168.11.2,product=n320,clock_source=external,time_source=external'.
[INFO] [MPM.Rhodium-0] init() called with args `master_clock_rate=245.76e6,mgmt_addr=192.168.11.2,product=n320,clock_source=external,time_source=external'
[INFO] [MPM.Rhodium-1] init() called with args `master_clock_rate=245.76e6,mgmt_addr=192.168.11.2,product=n320,clock_source=external,time_source=external'
[INFO] [MPM.PeriphManager] init() called with device args `master_clock_rate=245.76e6,mgmt_addr=192.168.10.2,product=n320,clock_source=external,time_source=external'.
[INFO] [MPM.Rhodium-0] init() called with args `master_clock_rate=245.76e6,mgmt_addr=192.168.10.2,product=n320,clock_source=external,time_source=external'
[INFO] [MPM.Rhodium-1] init() called with args `master_clock_rate=245.76e6,mgmt_addr=192.168.10.2,product=n320,clock_source=external,time_source=external'
[INFO] [MULTI_USRP]     1) catch time transition at pps edge
[INFO] [MULTI_USRP]     2) set times next pps (synchronously)
[INFO] [MPMD] Initializing 2 device(s) in parallel with args: mgmt_addr0=192.168.11.2,type0=n3xx,product0=n320,serial0=31DB241,claimed0=True,mgmt_addr1=192.168.10.2,type1=n3xx,product1=n320,serial1=31F43BD,claimed1=True,addr0=192.168.11.2,addr1=192.168.10.2,skip_boot_init=0,type=n3xx,master_clock_rate=245.76e6
[ERROR] [RPC] Someone tried to claim this device again (From: 192.168.11.1)
Traceback (most recent call last):
  File "/home/oln-ant/Documents/Full_Com_Example/Transceiver_Cal_Unit/Test_grc.py", line 335, in <module>
    main()
  File "/home/oln-ant/Documents/Full_Com_Example/Transceiver_Cal_Unit/Test_grc.py", line 311, in main
    tb = top_block_cls()
  File "/home/oln-ant/Documents/Full_Com_Example/Transceiver_Cal_Unit/Test_grc.py", line 137, in __init__
    '',
  File "/usr/local/lib/python3/dist-packages/gnuradio/uhd/__init__.py", line 125, in constructor_interceptor
    return old_constructor(*args)
  File "/usr/local/lib/python3/dist-packages/gnuradio/uhd/uhd_swig.py", line 3647, in make
    return _uhd_swig.usrp_sink_make(*args, **kwargs)
RuntimeError: RuntimeError: Error during RPC call to `claim'. Error message: Someone tried to claim this device again (From: 192.168.11.1)
[WARNING] [MPM.RPCServer] Someone tried to claim this device again (From: 192.168.11.1)
>>> Done (return code 1)

Relative to the softwares, I am using Gnuradio 3.8.3.0 and UHD 4.0 releases. 

Thank you for your help

 

Best regards

Test.grc
Description: Binary data

Test_grc.py
Description: Binary data