Source code for instruments.srs.srs345

#!/usr/bin/env python
"""
Provides support for the SRS 345 function generator.
"""

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


from enum import IntEnum

from instruments.units import ureg as u

from instruments.abstract_instruments import FunctionGenerator
from instruments.generic_scpi import SCPIInstrument
from instruments.util_fns import enum_property, unitful_property

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




class SRS345(SCPIInstrument, FunctionGenerator):
    """
    The SRS DS345 is a 30MHz function generator.

    Example usage:

    >>> import instruments as ik
    >>> import instruments.units as u
    >>> srs = ik.srs.SRS345.open_gpib('/dev/ttyUSB0', 1)
    >>> srs.frequency = 1 * u.MHz
    >>> print(srs.offset)
    >>> srs.function = srs.Function.triangle
    """

    # FIXME: need to add OUTX 1 here, but doing so seems to cause a syntax
    #        error on the instrument.

    # CONSTANTS #

    _UNIT_MNEMONICS = {
        FunctionGenerator.VoltageMode.peak_to_peak: "VP",
        FunctionGenerator.VoltageMode.rms: "VR",
        FunctionGenerator.VoltageMode.dBm: "DB",
    }

    _MNEMONIC_UNITS = {mnem: unit for unit, mnem in _UNIT_MNEMONICS.items()}

    # FunctionGenerator CONTRACT #

    def _get_amplitude_(self):
        resp = self.query("AMPL?").strip()

        return (float(resp[:-2]), self._MNEMONIC_UNITS[resp[-2:]])

    def _set_amplitude_(self, magnitude, units):
        self.sendcmd(f"AMPL {magnitude}{self._UNIT_MNEMONICS[units]}")

    # ENUMS ##



    class Function(IntEnum):
        """
        Enum containing valid output function modes for the SRS 345
        """

        sinusoid = 0
        square = 1
        triangle = 2
        ramp = 3
        noise = 4
        arbitrary = 5


    # PROPERTIES ##

    frequency = unitful_property(
        command="FREQ",
        units=u.Hz,
        doc="""
        Gets/sets the output frequency.

        :units: As specified, or assumed to be :math:`\\text{Hz}` otherwise.
        :type: `float` or `~pint.Quantity`
        """,
    )

    function = enum_property(
        command="FUNC",
        enum=Function,
        input_decoration=int,
        doc="""
        Gets/sets the output function of the function generator.

        :type: `~SRS345.Function`
        """,
    )

    offset = unitful_property(
        command="OFFS",
        units=u.volt,
        doc="""
        Gets/sets the offset voltage for the output waveform.

        :units: As specified, or assumed to be :math:`\\text{V}` otherwise.
        :type: `float` or `~pint.Quantity`
        """,
    )

    phase = unitful_property(
        command="PHSE",
        units=u.degree,
        doc="""
        Gets/sets the phase for the output waveform.

        :units: As specified, or assumed to be degrees (:math:`{}^{\\circ}`)
            otherwise.
        :type: `float` or `~pint.Quantity`
        """,
    )