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#1 2017-May-05 04:44:14

Asif509
Member
Registered: 2017-Apr-24
Posts: 5

Warplab

Hello everyone,

I was trying to execute  'wl_example_siso_ofdm_txrx.m' from WARPLab_Reference_Design_7.6.0 and WARPLab_Reference_Design_7.7.1 but i got the following error along with these warnings

Warning: Read IQ / Read RSSI request timed out.  Re-requesting samples.\n
> In wl_baseband_buffers>read_samples at 1757
  In wl_baseband_buffers>read_baseband_buffer at 1699
  In wl_baseband_buffers>readIQ at 1520
  In wl_baseband_buffers>wl_baseband_buffers.procCmd at 678
  In wl_baseband_buffers>wl_baseband_buffers.subsref at 120
  In wl_node>wl_node.wl_basebandCmd at 296
  In wl_example_siso_ofdm_txrx at 241
Warning: Read IQ / Read RSSI request timed out.  Re-requesting samples.\n
> In wl_baseband_buffers>read_samples at 1757
  In wl_baseband_buffers>read_baseband_buffer at 1699
  In wl_baseband_buffers>readIQ at 1520
  In wl_baseband_buffers>wl_baseband_buffers.procCmd at 678
  In wl_baseband_buffers>wl_baseband_buffers.subsref at 120
  In wl_node>wl_node.wl_basebandCmd at 296
  In wl_example_siso_ofdm_txrx at 241
ERROR:  Exceeded 2 retrys for current Read IQ / Read RSSI request
    Requested 131072 samples from buffer 2 starting from sample number 0
    Received 235 out of 369 packets from node before timeout.
    Please check the node and look at the ethernet traffic to isolate the issue.
??? Error using ==> wl_baseband_buffers>read_samples at 1755
Error:  Reached maximum number of retrys without a response... aborting.

Error in ==> wl_baseband_buffers>read_baseband_buffer at 1699
            read_samples(obj, node, myCmd, curr_samples, ifcIndex, start_sample,
            num_samples_this_req, start_sample_this_req, buffer_id, num_pkts,
            max_samples);

Error in ==> wl_baseband_buffers>readIQ at 1520
        rxSamples = read_baseband_buffer(obj, node, buffSel, myCmd, numSamps, offset,
        cmdStr);

Error in ==> wl_baseband_buffers>wl_baseband_buffers.procCmd at 678
                    out = readIQ(obj, node, buffSel, cmdStr, varargin{:});

Error in ==> wl_baseband_buffers>wl_baseband_buffers.subsref at 120
            varargout{:} = builtin('subsref', obj, S);

Error in ==> wl_node>wl_node.wl_basebandCmd at 296
                    out(n) = currNode.baseband.procCmd(n, currNode, varargin{:});

Error in ==> wl_example_siso_ofdm_txrx at 241
    rx_vec_air = wl_basebandCmd(node_rx, RF_RX_VEC, 'read_IQ', 0, TX_NUM_SAMPS);

I have connected my PC with a 1Gbps Ethernet Switch and two WARPV3 boards connected with same switch.
Is it something related to the ethernet port speed of the PC. I have a PC with 100Mbps Ethernet port 
I have run the same .m file in other PC with 1000Mbps Ethernet port , the run was successful.

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#2 2017-May-05 09:30:42

murphpo
Administrator
From: Mango Communications
Registered: 2006-Jul-03
Posts: 5159

Re: Warplab

I'm pretty sure the 100Mbps connection is the underlying problem. Your WARP nodes are returning packets with I/Q samples at 1Gbps, but the switch must send these 10x slower to your PC. As a result many packets are being lost. We have only characterized the WARPLab reference code with 1Gbps connections for WARP nodes and the host PC. If possible you should use a 1Gbps connection. Otherwise you will need to reduce the size of the read_iq requests to avoid dropping packets at the switch.

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