Ce programme a pour but de transformer le langage binaire de l oscilloscope numérique en des données exploitables sur l écran de l ordinateur. Il est également utilisé par le programme programme_principal_binaire_temp MODIFIED pour commander le déplacement du laser de lecture.
Voici le code réalisé sous Matlab, qui nous a permit de faire ce programme.
% version épurée par OX de LCread pour éviter de perdre du temps à lire des
% choses inutiles.
% Rq: vérifier que les choses supprimées sont bien inutiles :-)
% Pour celà, comparer avec LCread
% LCREAD read binary waveform file created by a LeCroy Oscilloscope
% W=LCREADOX(FILENAME) loads the waveform file into the workspace variable W.
% FILENAME can either be a variable or a string constant enclosed by quotes.
%
% The return value W is a record containing four elements:
%
W.INFO Waveform information, in readable formats. For
example Oscilloscope ID, sampling time and settings
% W.DESC Waveform information used for further calculations. For example Sampling rate
% W.Y Values sampled by the oscilloscope
%
W.X Array of time values corresponding to
W.Y. Time '0' marks the trigger event
%
% The routine was tested with files generated by a LC564A, Template LECROY_2_2
%
% See also LCPLOT LCPLOTEXT
%
%------------------------------------------------------
% (c)2001 Hochschule für Technik+Architektur Luzern
% Fachstelle Elektronik
% 6048 Horw, Switzerland
function wave=ReadLecroy(fn);
%---------------------------------------------------------------------------------------
% Seek offset in the header block
%---------------------------------------------------------------------------------------
fid=fopen(fn,'r');
if fid==-1
disp (sprintf('ERROR: file not found: %s', fn));
return
end;
data=fread(fid,50);
WAVEDESC=findstr('WAVEDESC', char(data(1:50)'))-1;
% subtract 1 because:
% - 1st byte in the File = Index [0]
% - 1st byte in the Matlab-Array = Index[1]
%---------------------------------------------------------------------------------------
% Define the addresses of the various informations in the file
% These addresses are valid for the template LECROY_2_2 and are subject to change in
% future revisions of the LeCroy firmware
%---------------------------------------------------------------------------------------
TESTED_TEMPLATE = 'LECROY_2_3';
%Addresses (WAVEDESC + address as stated in the LECROY template)
aTEMPLATE_NAME = WAVEDESC+ 16;
aCOMM_TYPE = WAVEDESC+ 32;
aCOMM_ORDER = WAVEDESC+ 34;
aWAVE_DESCRIPTOR = WAVEDESC+ 36; % length of the descriptor block
aUSER_TEXT
= WAVEDESC+ 40;
% length of the usertext block
aWAVE_ARRAY_1 = WAVEDESC+ 60; % length (in Byte) of the sample array
aVERTICAL_GAIN = WAVEDESC+ 156;
aHORIZ_INTERVAL = WAVEDESC+ 176;
aHORIZ_OFFSET = WAVEDESC+ 180;
%---------------------------------------------------------------------------------------
% determine the number storage format HIFIRST / LOFIRST (big endian / little endian)
%---------------------------------------------------------------------------------------
fseek(fid,aCOMM_ORDER,'bof');
COMM_ORDER=fread(fid,1,'int16');
fclose(fid);
% reopen the data file using the correct HIFIRST/LOFIRST format
if COMM_ORDER==0
fid=fopen(fn,'r','ieee-be'); % HIFIRST
else
fid=fopen(fn,'r','ieee-le'); % LOFIRST
end;
%---------------------------------------------------------------------------------------
% Get the waveform information
%--------------------------------------------------------------------------
% Instrument
wave.info.Filename = fn;
% Vertical settings
VERTICAL_GAIN
=
ReadFloat (fid, aVERTICAL_GAIN);
% Horizontal settings
HORIZ_INTERVAL = ReadFloat(fid, aHORIZ_INTERVAL);
HORIZ_OFFSET = ReadDouble(fid, aHORIZ_OFFSET);
%---------------------------------------------------------------------------------------
% Read samples array (Plain binary ADC values)
%---------------------------------------------------------------------------------------
COMM_TYPE = ReadWord(fid, aCOMM_TYPE);
WAVE_DESCRIPTOR = ReadLong(fid, aWAVE_DESCRIPTOR);
USER_TEXT = ReadLong(fid, aUSER_TEXT);
WAVE_ARRAY_1 = ReadLong(fid, aWAVE_ARRAY_1);
fseek(fid, WAVEDESC + WAVE_DESCRIPTOR + USER_TEXT, 'bof');
if COMM_TYPE == 0 % byte
wave.y=fread(fid,WAVE_ARRAY_1, 'int8');
% Transform the ADC values to voltages and create corresponding array of
% time
wave.y = VERTICAL_GAIN * wave.y ;
wave.x = [0:(WAVE_ARRAY_1-1)]'*HORIZ_INTERVAL ;
else % word
wave.y=fread(fid,WAVE_ARRAY_1, 'int16');
wave.y = VERTICAL_GAIN * wave.y ;
wave.x = [0:(WAVE_ARRAY_1-1)/2]'*HORIZ_INTERVAL + HORIZ_OFFSET ;
end;
%---------------------------------------------------------------------------------------
% close the waveform file
%---------------------------------------------------------------------------------------
fclose(fid);
%=======================================================================================
% Support functions
%=======================================================================================
%---------------------------------------------------------------------------------------
% Read 16Bit signed Word
%---------------------------------------------------------------------------------------
function w=ReadWord(fid, Addr)
fseek(fid,Addr,'bof');
w=fread(fid,1,'int16');
%---------------------------------------------------------------------------------------
% Read 32Bit signed Long
%---------------------------------------------------------------------------------------
function l=ReadLong(fid, Addr)
fseek(fid,Addr,'bof');
l=fread(fid,1,'int32');
%---------------------------------------------------------------------------------------
% Read 32Bit IEEE Float
%---------------------------------------------------------------------------------------
function f=ReadFloat(fid, Addr)
fseek(fid,Addr,'bof');
f=fread(fid,1,'float32');
%---------------------------------------------------------------------------------------
% Read 64Bit IEEE Double
%---------------------------------------------------------------------------------------
function d=ReadDouble(fid, Addr)
fseek(fid,Addr,'bof');
d=fread(fid,1,'float64');
