diff --git a/@MyLogger/MyLogger.m b/@MyLogger/MyLogger.m
index a150187..8e85d29 100644
--- a/@MyLogger/MyLogger.m
+++ b/@MyLogger/MyLogger.m
@@ -1,105 +1,137 @@
 % Generic logger that executes MeasFcn according to MeasTimer, stores the
 % results and optionally continuously saves them. MeasFcn should be a
-% function with no arguments.
-classdef MyLogger
+% function with no arguments. Saving functionality works properly if 
+% MeasFcn returns a number or array of numbers, while intrinsically the 
+% logger can store any kind of outputs.
+classdef MyLogger < handle
     properties
         MeasTimer; % Timer object
         MeasFcn;
         save_cont = false;
         save_file = '';
         data_headers = []; % Cell array of column headers
     end
     
     properties (SetAccess=protected, GetAccess=public)
         %Trace = MyTrace(); % Trace object for communication with Daq
         timestamps = []; % Times at which data was aqcuired
         data = []; % Stored cell array of measurements
         last_meas_stat = 2; % If last measurement was succesful
         %0-false, 1-true, 2-never measured 
     end
     
     properties (Constant=true)
         TIME_FMT = '%14.3f'; % Save time as posixtime up to ms precision
+        DATA_FIELD_WIDTH = '24';
         DATA_FMT = '%24.14e'; % Save data as reals with 14 decimal digits
     end
     
     methods
         function this = MyLogger(MeasFcn,varargin)
             this.MeasFcn = MeasFcn;            
             % Create and confitugure timer
             this.MeasTimer = timer(varargin{:});
             this.MeasTimer.BusyMode = 'queue';
             this.MeasTimer.ExecutionMode = 'FixedRate';
             this.MeasTimer.TimerFcn = @(~,event)LoggerFcn(this,event); 
         end
         
         function delete(this)         
             %stop and delete the timer
             stop(this.T);
             delete(this.T);
         end
         
         function LoggerFcn(this, event)
             time = datetime(event.Data.time);
             try
                 meas_result = this.MeasFcn();
                 % append measurement result together with time stamp
                 this.timestamps=[this.timestamps; time];
                 this.data=[this.data, {meas_result}];
                 this.last_meas_stat=1; % last measurement ok
             catch
                 warning(['Logger cannot take measurement at time = ',...
                     datestr(time)]);
                 this.last_meas_stat=0; % last measurement not ok
             end
             
             % save the point to file if continuous saving is enabled and
             % last measurement was succesful
             if this.save_cont&&(this.last_meas_stat==1)
                 try
-                    exid = exist(this.save_file,'file');
-                    fid = fopen(this.save_file,'a');
-                    if exid==0
-                        % if the file was just created, write column
-                        % headers
+                    exstat = exist(this.save_file,'file');
+                    if exstat==0
+                        % if the file does not exist, create it and write
+                        % header names
+                        createFile(this.save_file)
+                        fid = fopen(this.save_file,'w');
                         writeColumnHeaders(this, fid);
+                    else
+                        % otherwise open for appending
+                        fid = fopen(this.save_file,'a');
                     end
                     fprintf(fid, this.TIME_FMT, posixtime(time));
                     fprintf(fid, this.DATA_FMT, meas_result);
                     fprintf(fid,'\r\n');
                     fclose(fid);
                 catch
                     warning(['Logger cannot save data at time = ',...
                         datestr(time)]);
+                    % Try closing fid in case it is still open
+                    try
+                        fclose(fid);
+                    catch
+                    end
                 end
             end
         end
         
+        % save the entire data record
         function saveLog(this)
-            exid = exist(this.save_file,'file');
-            if exid~=0
-                % if the file already exists
+            try
+            	createFile(this.save_file);
+                fid = fopen(this.save_file,'w');
                 writeColumnHeaders(this, fid);
+                for i=1:length(this.timestamps)
+                    fprintf(fid, this.TIME_FMT,...
+                        posixtime(this.timestamps(i)));
+                    fprintf(fid, this.DATA_FMT,...
+                        this.data{i});
+                    fprintf(fid,'\r\n');
+                end
+                fclose(fid);
+            catch
+                warning('Data was not saved');
+                % Try closing fid in case it is still open
+                try
+                    fclose(fid);
+                catch
+                end
             end
-            fid = fopen(this.save_file,'w');
-            fclose(fid);
+        end
+        
+        function clearLog(this)
+            this.timestamps = [];
+            this.data = [];
         end
                
         function writeColumnHeaders(this, fid)
             fprintf(fid, '  POSIX time, s');
             for i=1:length(this.data_headers)
-                fprintf(fid, '24%s', this.data_headers{i});
+                fprintf(fid, ['%',this.DATA_FIELD_WIDTH,'s'],...
+                    this.data_headers{i});
             end
             fprintf(fid,'\r\n');
         end
         
         function start(this)
             start(this.T)
         end
         
         function stop(this)
             stop(this.T)
         end
     end
 end
 
diff --git a/Utility functions/createFile.m b/Utility functions/createFile.m
index e7a23b3..23ea39d 100644
--- a/Utility functions/createFile.m	
+++ b/Utility functions/createFile.m	
@@ -1,40 +1,42 @@
+% Function creates file, if necessary together with subdirectory, and shows
+% a dialog if the file with such name already exisits
 function file_created=createFile(fullfilename,varargin)
     p=inputParser();
     addRequired(p,'fullfilename',@ischar);
     addParameter(p,'overwrite',false,@islogical);
     parse(p,fullfilename,varargin{:});
 
     file_created=true;
     
     %Creates save directory if it does not exist
     [save_dir,~,~]=fileparts(fullfilename);
     if ~exist(save_dir,'dir')
         mkdir(save_dir)
     end
 
     if exist(fullfilename,'file') && ~p.Results.overwrite
         switch questdlg('Would you like to overwrite?',...
                 'File already exists', 'Yes', 'No', 'No')
             case 'Yes'
                 fprintf('Overwriting file at %s\n',fullfilename);
             otherwise
                 warning('No file written as %s already exists',...
                     fullfilename);
                 file_created=false;
                 return
         end
     end
 
     %Creates the file
     fileID=fopen(fullfilename,'w');
     fclose(fileID);
 
     %MATLAB returns -1 for the fileID if the file could not be
     %opened
     if fileID==-1
         errordlg(sprintf('File %s could not be created.',...
             fullfilename),'File error');
         file_created=false;
         return
     end
 end
\ No newline at end of file