plx_ad

 plx_ad(filename, channel): Read a/d data from a .plx file

 [adfreq, n, ts, fn, ad] = plx_ad(filename, ch)

 INPUT:
   filename - if empty string, will use File Open dialog
   channel - 0 - based channel number

           a/d data come in fragments. Each fragment has a timestamp
           and a number of a/d data points. The timestamp corresponds to
           the time of recording of the first a/d value in this fragment.
           All the data values stored in the vector ad. 
 OUTPUT:
   n - total number of data points 
   ts - array of fragment timestamps (one timestamp for fragment, in seconds)
   fn - number of data points in each fragment
   ad - array of raw a/d values

0001 function [adfreq, n, ts, fn, ad] = plx_ad(filename, ch)
0002 % plx_ad(filename, channel): Read a/d data from a .plx file
0003 %
0004 % [adfreq, n, ts, fn, ad] = plx_ad(filename, ch)
0005 %
0006 % INPUT:
0007 %   filename - if empty string, will use File Open dialog
0008 %   channel - 0 - based channel number
0009 %
0010 %           a/d data come in fragments. Each fragment has a timestamp
0011 %           and a number of a/d data points. The timestamp corresponds to
0012 %           the time of recording of the first a/d value in this fragment.
0013 %           All the data values stored in the vector ad.
0014 % OUTPUT:
0015 %   n - total number of data points
0016 %   ts - array of fragment timestamps (one timestamp for fragment, in seconds)
0017 %   fn - number of data points in each fragment
0018 %   ad - array of raw a/d values
0019 
0020 if(nargin ~= 2)
0021    disp('2 input arguments are required')
0022    return
0023 end
0024 
0025 i = 0;
0026 n = 0;
0027 ts = 0;
0028 fn = 0;
0029 ad = 0;
0030 
0031 if(isempty(filename))
0032    [fname, pathname] = uigetfile('*.plx', 'Select a plx file');
0033     filename = strcat(pathname, fname);
0034 end
0035 
0036 fid = fopen(filename, 'r');
0037 if(fid == -1)
0038     disp('cannot open file');
0039    return
0040 end
0041 
0042 % calculate file size
0043 fseek(fid, 0, 'eof');
0044 fsize = ftell(fid);
0045 fseek(fid, 0, 'bof');
0046 
0047 
0048 disp(strcat('file = ', filename));
0049 
0050 % read file header
0051 header = fread(fid, 64, 'int32');
0052 freq = header(35);  % frequency
0053 ndsp = header(36);  % number of dsp channels
0054 nevents = header(37); % number of external events
0055 nslow = header(38);  % number of slow channels
0056 npw = header(39);  % number of points in wave
0057 npr = header(40);  % number of points before threshold
0058 tscounts = fread(fid, [5, 130], 'int32');
0059 wfcounts = fread(fid, [5, 130], 'int32');
0060 evcounts = fread(fid, [1, 512], 'int32');
0061 
0062 % A/D counts are stored in evcounts (301, 302, etc.)
0063 count = 0;
0064 if evcounts(301+ch) > 0
0065     count = evcounts(301+ch);
0066     ad = 1:count;
0067 end
0068 
0069 % skip DSP and Event headers
0070 fseek(fid, 1020*ndsp + 296*nevents, 'cof');
0071 
0072 % read one A/D header and get the frequency
0073 adheader = fread(fid, 74, 'int32');
0074 adfreq = adheader(10);
0075 
0076 % skip all other a/d headers
0077 fseek(fid, 296*(nslow-1), 'cof');
0078 
0079 record = 0;
0080 
0081 wf = zeros(1, npw);
0082 adpos = 1;
0083 
0084 while feof(fid) == 0
0085    type = fread(fid, 1, 'int16');
0086     upperbyte = fread(fid, 1, 'int16');
0087     timestamp = fread(fid, 1, 'int32');
0088     channel = fread(fid, 1, 'int16');
0089    unit = fread(fid, 1, 'int16');
0090    nwf = fread(fid, 1, 'int16');
0091    nwords = fread(fid, 1, 'int16');
0092    if nwords > 0
0093       wf = fread(fid, [1 nwords], 'int16');
0094    end
0095    if nwords > 0
0096       if type == 5
0097          if channel == ch 
0098             i = i + 1;
0099             n = n + nwords;
0100              ts(i) = timestamp/freq;
0101             fn(i) = nwords;
0102             if count > 0
0103                 if adpos+nwords-1 <= count
0104                     ad(adpos:adpos+nwords-1) = wf(1:nwords);
0105                     adpos = adpos + nwords;
0106                 else
0107                     for i=1:nwords
0108                         ad(adpos) = wf(i); adpos = adpos + 1;
0109                     end
0110                 end
0111             else
0112                 ad = [ad wf(1, 1:nwords)];
0113             end
0114            end
0115       end
0116    end
0117    
0118    record = record + 1;
0119    if mod(record, 1000) == 0
0120        disp(sprintf('records %d points %d (%.1f%%)', record, n, 100*ftell(fid)/fsize));
0121    end
0122 
0123    if feof(fid) == 1
0124       break
0125    end
0126    
0127 end
0128 
0129 if adpos-1 < count
0130    ad = ad(1:adpos-1);
0131 end
0132 
0133 disp(strcat('number of data points = ', num2str(n)));
0134 
0135 fclose(fid);