readDAQData.m

function [mRcvData,vRcvData] = readDAQData(dir_, frameNum, numSample)

chanls = ones(1,128);
reRoute = true;

vRcvData = zeros(numSample, 128, frameNum);

disp('>>> reading DAQ data');
for frameN = 1:1:frameNum
    if(mod(frameN,frameNum/4)==0)
        disp(['    ' num2str(round(frameN/frameNum*100)) '%...']);
    end
    
    % Signal assignement to transducer element
    if (reRoute)
        chRout = [0 16 32 48 64 80 96 112 1 17 33 49 65 81 97 113 2 18 34 50 66 82 98 114 ...
            3 19 35 51 67 83 99 115 4 20 36 52 68 84 100 116 5 21 37 53 69 85 101 117 ...
            6 22 38 54 70 86 102 118 7 23 39 55 71 87 103 119 8 24 40 56 72 88 104 120 ...
            9 25 41 57 73 89 105 121 10 26 42 58 74 90 106 122 11 27 43 59 75 91 107 ...
            123 12 28 44 60 76 92 108 124 13 29 45 61 77 93 109 125 14 30 46 62 78 94 ...
            110 126 15 31 47 63 79 95 111 127];
    else    % show channel signals
        chRout = [0:127];
    end
    
    % Filtering of channel data
    % [B,A] = BUTTER(5,[.1,.9]);   % 5th order butterworth filter
    % no filtering
    B = 1; A = 1;
    
    for i = 1:128
        if (chanls(i) == 1)
            % create the file name
            chlInd = i-1;
            if (chlInd<10)
                tag = ['00',num2str(chlInd)];
            elseif (chlInd<100)
                tag = ['0',num2str(chlInd)];
            else
                tag = num2str(chlInd);
            end
            filename = ['CH',tag,'.daq'];
            
            % open channel file
            fid = fopen([dir_ '\' filename],'r');
            
            if (fid == -1), continue; end
            
            % read header
            hdr = fread(fid, 3, 'int32');
            if (i == 1)
                numFrame = hdr(2);      % number of frames acquired
                lLength  = hdr(3);      % length of each line in samples
            end
            % jump to requested frame
            fseek( fid, (frameN-1) * ( lLength * 2), 'cof');
            
            % read channel data and correct the mapping
            dataformat = 'int16';
            ind = 1 + chRout(i);
            RFframe(:,ind)       = filter( B, A, fread(fid, [lLength], dataformat ) );
            % close channel file
            fclose(fid);
        end
    end
    
    vRcvData(:,:,frameN) = RFframe;
end

mRcvData = mean(vRcvData,3);
end