IN: import visa

IN: rm=visa.ResourceManager()

IN: print rm.list_resources()

(u'ASRL4::INSTR',)

IN: inst=rm.open_resource("ASRL4::INSTR")

IN: print inst.query("*IDN?")

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

  File "C:Anaconda2libsite-packagespyvisa-1.8-py2.7.eggpyvisaresourcesmessagebased.py", line 407, in query
    return self.read()

  File "C:Anaconda2libsite-packagespyvisa-1.8-py2.7.eggpyvisaresourcesmessagebased.py", line 332, in read
    message = self.read_raw().decode(enco)

  File "C:Anaconda2libsite-packagespyvisa-1.8-py2.7.eggpyvisaresourcesmessagebased.py", line 306, in read_raw
    chunk, status = self.visalib.read(self.session, size)

  File "C:Anaconda2libsite-packagespyvisa-1.8-py2.7.eggpyvisactwrapperfunctions.py", line 1582, in read
    ret = library.viRead(session, buffer, count, byref(return_count))

  File "C:Anaconda2libsite-packagespyvisa-1.8-py2.7.eggpyvisactwrapperhighlevel.py", line 188, in _return_handler

    raise errors.VisaIOError(ret_value)