device.py 文件源码

def ai_lowpass_cutoff_freq_discrete_vals(self):
        """
        List[float]: Indicates the set of discrete lowpass cutoff
            frequencies supported by this device. If the device supports
            ranges of lowpass cutoff frequencies, use
            **ai_lowpass_cutoff_freq_range_vals** to determine supported
            frequencies.
        """
        cfunc = (lib_importer.windll.
                 DAQmxGetDevAILowpassCutoffFreqDiscreteVals)
        if cfunc.argtypes is None:
            with cfunc.arglock:
                if cfunc.argtypes is None:
                    cfunc.argtypes = [
                        ctypes_byte_str,
                        wrapped_ndpointer(dtype=numpy.float64,
                        flags=('C','W')), ctypes.c_uint]

        temp_size = 0
        while True:
            val = numpy.zeros(temp_size, dtype=numpy.float64)

            size_or_code = cfunc(
                self._name, val, temp_size)

            if is_array_buffer_too_small(size_or_code):
                # Buffer size must have changed between calls; check again.
                temp_size = 0
            elif size_or_code > 0 and temp_size == 0:
                # Buffer size obtained, use to retrieve data.
                temp_size = size_or_code
            else:
                break

        check_for_error(size_or_code)

        return val.tolist()