How to use the nidmm.visatype function in nidmm

For the NI 4050 and NI 4060, the error codes returned for self-test
                failures include the following:

                -  NIDMM_ERROR_AC_TEST_FAILURE
                -  NIDMM_ERROR_DC_TEST_FAILURE
                -  NIDMM_ERROR_RESISTANCE_TEST_FAILURE

                These error codes indicate that the DMM should be repaired.

                For the NI 4080/4081/4082 and the NI 4070/4071/4072, the error code
                returned for a self-test failure is NIDMM_ERROR_SELF_TEST_FAILURE.
                This error code indicates that the DMM should be repaired.
        '''
        vi_ctype = visatype.ViSession(self._vi)  # case 1
        self_test_result_ctype = visatype.ViInt16()  # case 14
        self_test_message_ctype = (visatype.ViChar * 256)()  # case 11
        error_code = self._library.niDMM_self_test(vi_ctype, ctypes.pointer(self_test_result_ctype), self_test_message_ctype)
        errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
        return int(self_test_result_ctype.value), self_test_message_ctype.value.decode(self._encoding)

For the NI 4050 and NI 4060, the error codes returned for self-test
                failures include the following:

                -  NIDMM_ERROR_AC_TEST_FAILURE
                -  NIDMM_ERROR_DC_TEST_FAILURE
                -  NIDMM_ERROR_RESISTANCE_TEST_FAILURE

                These error codes indicate that the DMM should be repaired.

                For the NI 4080/4081/4082 and the NI 4070/4071/4072, the error code
                returned for a self-test failure is NIDMM_ERROR_SELF_TEST_FAILURE.
                This error code indicates that the DMM should be repaired.
        '''
        vi_ctype = visatype.ViSession(self._vi)  # case 1
        self_test_result_ctype = visatype.ViInt16()  # case 14
        self_test_message_ctype = (visatype.ViChar * 256)()  # case 11
        error_code = self._library.niDMM_self_test(vi_ctype, ctypes.pointer(self_test_result_ctype), self_test_message_ctype)
        errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
        return int(self_test_result_ctype.value), self_test_message_ctype.value.decode(self._encoding)

def self_cal(self):
        '''self_cal

        For the NI 4080/4081/4082 and the NI 4070/4071/4072, executes the
        self-calibration routine to maintain measurement accuracy.

        Note:
        This function calls reset, and any configurations previous to
        the call will be lost. All attributes will be set to their default
        values after the call returns.
        '''
        vi_ctype = visatype.ViSession(self._vi)  # case 1
        error_code = self._library.niDMM_SelfCal(vi_ctype)
        errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
        return

def _get_error(self):
        '''_get_error

        Returns the error information associated with the
        **Instrument_Handle**. This function retrieves and then clears the
        error information for the session. If you leave the
        **Instrument_Handle** unwired, this function retrieves and then clears
        the error information for the process.

        Returns:
            error_code (int): Returns the **error_code** for the session or execution thread. If you
                pass 0 for the **Buffer_Size**, you can pass VI_NULL for this
                parameter.
        '''
        vi_ctype = visatype.ViSession(self._vi)  # case 1
        error_code_ctype = visatype.ViStatus()  # case 14
        buffer_size_ctype = visatype.ViInt32()  # case 7
        description_ctype = None  # case 12
        error_code = self._library.niDMM_GetError(vi_ctype, ctypes.pointer(error_code_ctype), buffer_size_ctype, description_ctype)
        errors.handle_error(self, error_code, ignore_warnings=True, is_error_handling=True)
        buffer_size_ctype = visatype.ViInt32(error_code)  # case 7.5
        description_ctype = (visatype.ViChar * buffer_size_ctype.value)()  # case 12.5
        error_code = self._library.niDMM_GetError(vi_ctype, ctypes.pointer(error_code_ctype), buffer_size_ctype, description_ctype)
        errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=True)
        return int(error_code_ctype.value), description_ctype.value.decode(self._encoding)

Tip:
        This method requires repeated capabilities (usually channels). If called directly on the
        nidmm.Session object, then the method will use all repeated capabilities in the session.
        You can specify a subset of repeated capabilities using the Python index notation on an
        nidmm.Session instance, and calling this method on the result.:

            session['0,1']._get_attribute_vi_boolean(attribute_id)

        Args:
            attribute_id (int): Pass the ID of an attribute.

        Returns:
            attribute_value (bool): Returns the current value of the attribute. Pass the address of a
                ViBoolean variable.
        '''
        vi_ctype = visatype.ViSession(self._vi)  # case 1
        channel_name_ctype = ctypes.create_string_buffer(self._repeated_capability.encode(self._encoding))  # case 2
        attribute_id_ctype = visatype.ViAttr(attribute_id)  # case 9
        attribute_value_ctype = visatype.ViBoolean()  # case 14
        error_code = self._library.niDMM_GetAttributeViBoolean(vi_ctype, channel_name_ctype, attribute_id_ctype, ctypes.pointer(attribute_value_ctype))
        errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
        return bool(attribute_value_ctype.value)

The valid range is 0–86400000. The default value is
                NIDMM_VAL_TIME_LIMIT_AUTO (-1). The DMM calculates the timeout
                automatically.

        Returns:
            reading_array (list of float): An array of measurement values.

                Note:
                The size of the **Reading_Array** must be at least the size that you
                specify for the **Array_Size** parameter.
            actual_number_of_points (int): Indicates the number of measured values actually retrieved from the DMM.
        '''
        vi_ctype = visatype.ViSession(self._vi)  # case 1
        maximum_time_ctype = visatype.ViInt32(maximum_time)  # case 9
        array_size_ctype = visatype.ViInt32(array_size)  # case 8
        reading_array_ctype = (visatype.ViReal64 * array_size)()  # case 13
        actual_number_of_points_ctype = visatype.ViInt32()  # case 14
        error_code = self._library.niDMM_FetchMultiPoint(vi_ctype, maximum_time_ctype, array_size_ctype, reading_array_ctype, ctypes.pointer(actual_number_of_points_ctype))
        errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
        return [float(reading_array_ctype[i]) for i in range(array_size_ctype.value)]

open cable compensation **Conductance** and **Susceptance** values. You
        can use the return values of this function as inputs to
        configure_open_cable_comp_values.

        This function returns an error if the value of the function
        attribute is not set to NIDMM_VAL_CAPACITANCE (1005) or
        NIDMM_VAL_INDUCTANCE (1006).

        Returns:
            conductance (float): **conductance** is the measured value of open cable compensation
                **conductance**.
            susceptance (float): **susceptance** is the measured value of open cable compensation
                **susceptance**.
        '''
        vi_ctype = visatype.ViSession(self._vi)  # case 1
        conductance_ctype = visatype.ViReal64()  # case 14
        susceptance_ctype = visatype.ViReal64()  # case 14
        error_code = self._library.niDMM_PerformOpenCableComp(vi_ctype, ctypes.pointer(conductance_ctype), ctypes.pointer(susceptance_ctype))
        errors.handle_error(self, error_code, ignore_warnings=False, is_error_handling=False)
        return float(conductance_ctype.value), float(susceptance_ctype.value)