For any Instrument that does not have a self.ask('*IDN?') a warning is generated. This is inconvenient for all derived classes that do not have a VISA interface.

The warning is generated here:

https://github.com/QCoDeS/Qcodes/blob/master/qcodes/instrument/base.py#L130

A minimal example:

from qcodes import Instrument

class dummy(Instrument):
    pass

d=dummy(name='test')
idn=d.get_idn()

Can we remove the warning (or change it into a logging.info)?

@giulioungaretti