'parse READ_ANDX response message to extract the raw bytes
return the raw bytes: return rawbytes
\'\' if err'

def PARSE_READ_ANDX_Response(self, data):

    try:
        (wct, andxcmd, rsrv1, andxoffset) = struct.unpack('<BBBH', data[:5])
        (remaining, datacompactmode, resv2) = struct.unpack('<HHH', data[5:11])
        (datalenlow, dataoffset, datalenhigh) = struct.unpack('<HHI', data[11:19])
        (bytecount, padding) = struct.unpack('<HB', data[25:28])
        return data[28:(27 + bytecount)]
    except:
        return ''
