Source code for instruments.abstract_instruments.oscilloscope

#!/usr/bin/env python
"""
Provides an abstract base class for oscilloscope instruments
"""

# IMPORTS #####################################################################


import abc

from instruments.abstract_instruments import Instrument

# CLASSES #####################################################################




class Oscilloscope(Instrument, metaclass=abc.ABCMeta):
    """
    Abstract base class for oscilloscope instruments.

    All applicable concrete instruments should inherit from this ABC to
    provide a consistent interface to the user.
    """



    class Channel(metaclass=abc.ABCMeta):
        """
        Abstract base class for physical channels on an oscilloscope.

        All applicable concrete instruments should inherit from this ABC to
        provide a consistent interface to the user.
        """

        # PROPERTIES #

        @property
        @abc.abstractmethod
        def coupling(self):
            """
            Gets/sets the coupling setting for the oscilloscope. This is an
            abstract method.

            :type: `~enum.Enum`
            """
            raise NotImplementedError

        @coupling.setter
        @abc.abstractmethod
        def coupling(self, newval):
            raise NotImplementedError




    class DataSource(metaclass=abc.ABCMeta):
        """
        Abstract base class for data sources (physical channels, math, ref) on
        an oscilloscope.

        All applicable concrete instruments should inherit from this ABC to
        provide a consistent interface to the user.
        """

        def __init__(self, parent, name):
            self._parent = parent
            self._name = name
            self._old_dsrc = None

        def __enter__(self):
            self._old_dsrc = self._parent.data_source
            if self._old_dsrc != self:
                # Set the new data source, and let __exit__ cleanup.
                self._parent.data_source = self
            else:
                # There's nothing to do or undo in this case.
                self._old_dsrc = None

        def __exit__(self, type, value, traceback):
            if self._old_dsrc is not None:
                self._parent.data_source = self._old_dsrc

        def __eq__(self, other):
            if not isinstance(other, type(self)):
                return NotImplemented

            return other.name == self.name

        __hash__ = None

        # PROPERTIES #

        @property
        @abc.abstractmethod
        def name(self):
            """
            Gets the name of the channel. This is an abstract property.

            :type: `str`
            """
            raise NotImplementedError

        # METHODS #



        @abc.abstractmethod
        def read_waveform(self, bin_format=True):
            """
            Gets the waveform of the specified data source channel. This is an
            abstract property.

            :param bool bin_format: If the waveform should be transfered in binary
                (``True``) or ASCII (``False``) formats.
            :return: The waveform with both x and y components.
            :rtype: `numpy.ndarray`
            """
            raise NotImplementedError



    # PROPERTIES #

    @property
    @abc.abstractmethod
    def channel(self):
        """
        Gets an iterator or list for easy Pythonic access to the various
        channel objects on the oscilloscope instrument. Typically generated
        by the `~instruments.util_fns.ProxyList` helper.
        """
        raise NotImplementedError

    @property
    @abc.abstractmethod
    def ref(self):
        """
        Gets an iterator or list for easy Pythonic access to the various
        ref data sources objects on the oscilloscope instrument. Typically
        generated by the `~instruments.util_fns.ProxyList` helper.
        """
        raise NotImplementedError

    @property
    @abc.abstractmethod
    def math(self):
        """
        Gets an iterator or list for easy Pythonic access to the various
        math data sources objects on the oscilloscope instrument. Typically
        generated by the `~instruments.util_fns.ProxyList` helper.
        """
        raise NotImplementedError

    # METHODS #



    @abc.abstractmethod
    def force_trigger(self):
        """
        Forces a trigger event to occur on the attached oscilloscope.
        """
        raise NotImplementedError