Reads the contents of the Comtrade .dat file and store them in a
        private variable.
        
        For accessing a specific channel data, see methods getAnalogData and
        getDigitalData.

def ReadDataFile(self):
        """
        Reads the contents of the Comtrade .dat file and store them in a
        private variable.
        
        For accessing a specific channel data, see methods getAnalogData and
        getDigitalData.
        """
        if os.path.isfile(self.filename[0:-4] + '.dat'):
            filename = self.filename[0:-4] + '.dat'
    
        elif os.path.isfile(self.filename[0:-4] + '.DAT'):
            filename = self.filename[0:-4] + '.DAT'
        
        else:
            print "Data file File not found."
            return 0
        
        self.filehandler = open(filename,'rb')
        self.DatFileContent = self.filehandler.read()
    
        # END READING .dat FILE.
        self.filehandler.close() # Close file.        
        
        return 1