Connecting to SM 70-45D by Delta Elektronika in Python

Instrument Card

The Delta Elektronika BV Model SM70-45D Programmable DC Power Supply 0-70V 0-45A

Device Specification: here

Manufacturer card: DELTA ELEKTRONIKA

Telonic Instruments is one of the leading Suppliers of Kikusui, Rigol and Lab-Power power supplies and frequency converters.

• Headquarters: UK
• Yearly Revenue (millions, USD):
• Vendor Website: here

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Connect to the SM 70-45D in Python

Read our guide for turning Python scripts into Flojoy nodes.

Flojoy

PROTOCOLS > SCPI

📄 IDN

Query a device's identity through the universal *IDN? SCPI command.

📄 MEASURE VOLTAGE

Query an instrument's measured output voltage, such as a DMM or power supply.

📄 SCPI WRITE

Write a SCPI command to a connected bench-top instrument and return the result.

PyMeasure

Here is a Python script that uses Pymeasure to connect to a SM 70-45D Power Supply:

from pymeasure.instruments import Instrument
from pymeasure.instruments.validators import strict_range
from time import sleep
from numpy import linspace

class SM7045D(Instrument):
    """ This is the class for the SM 70-45 D power supply.

    ... (code omitted for brevity) ...
    """

    # Define the voltage and current ranges
    VOLTAGE_RANGE = [0, 70]
    CURRENT_RANGE = [0, 45]

    # Define the instrument properties
    voltage = Instrument.control(
        "SO:VO?", "SO:VO %g",
        """ A floating point property that represents the output voltage
        setting of the power supply in Volts. This property can be set. """,
        validator=strict_range,
        values=VOLTAGE_RANGE
    )

    current = Instrument.control(
        "SO:CU?", "SO:CU %g",
        """ A floating point property that represents the output current of
        the power supply in Amps. This property can be set. """,
        validator=strict_range,
        values=CURRENT_RANGE
    )

    max_voltage = Instrument.control(
        "SO:VO:MA?", "SO:VO:MA %g",
        """ A floating point property that represents the maximum output
        voltage of the power supply in Volts. This property can be set. """,
        validator=strict_range,
        values=VOLTAGE_RANGE
    )

    max_current = Instrument.control(
        "SO:CU:MA?", "SO:CU:MA %g",
        """ A floating point property that represents the maximum output
        current of the power supply in Amps. This property can be set. """,
        validator=strict_range,
        values=CURRENT_RANGE
    )

    measure_voltage = Instrument.measurement(
        "ME:VO?",
        """ Measures the actual output voltage of the power supply in
        Volts. """,
    )

    measure_current = Instrument.measurement(
        "ME:CU?",
        """ Measures the actual output current of the power supply in
        Amps. """,
    )

    rsd = Instrument.measurement(
        "SO:FU:RSD?",
        """ Check whether remote shutdown is enabled/disabled and thus if the
        output of the power supply is disabled/enabled. """,
    )

    def __init__(self, adapter, name="Delta Elektronika SM 70-45 D", **kwargs):
        super().__init__(
            adapter,
            name,
            **kwargs
        )

    def enable(self):
        """
        Disable remote shutdown, hence output will be enabled.
        """
        self.write("SO:FU:RSD 0")

    def disable(self):
        """
        Enables remote shutdown, hence input will be disabled.
        """
        self.write("SO:FU:RSD 1")

    def ramp_to_current(self, target_current, current_step=0.1):
        """
        Gradually increase/decrease current to target current.

        :param target_current: Float that sets the target current (in A)
        :param current_step: Optional float that sets the current steps
                             / ramp rate (in A/s)
        """

        curr = self.current
        n = round(abs(curr - target_current) / current_step) + 1
        for i in linspace(curr, target_current, n):
            self.current = i
            sleep(0.1)

    def ramp_to_zero(self, current_step=0.1):
        """
        Gradually decrease the current to zero.

        :param current_step: Optional float that sets the current steps
                             / ramp rate (in A/s)
        """

        self.ramp_to_current(0, current_step)

    def shutdown(self):
        """
        Set the current to 0 A and disable the output of the power source.
        """
        self.ramp_to_zero()
        self.disable()
        super().shutdown()

# Connect to the power supply
source = SM7045D("GPIB::8")

# Example usage
source.ramp_to_zero(1)               # Set output to 0 before enabling
source.enable()                      # Enables the output
source.current = 1                   # Sets a current of 1 Amps

This script defines a class SM7045D that represents the SM 70-45 D power supply. It provides methods to control the power supply, such as setting the voltage and current, enabling/disabling the output, and ramping the current up or down. The script also includes an example usage at the end, where it connects to the power supply and performs some operations.