physical_channel.py 文件源码

def ai_input_srcs(self):
        """
        List[str]: Indicates the list of input sources supported by the
            channel. Channels may support using the signal from the I/O
            connector or one of several calibration signals.
        """
        cfunc = lib_importer.windll.DAQmxGetPhysicalChanAIInputSrcs
        if cfunc.argtypes is None:
            with cfunc.arglock:
                if cfunc.argtypes is None:
                    cfunc.argtypes = [
                        ctypes_byte_str, ctypes.c_char_p, ctypes.c_uint]

        temp_size = 0
        while True:
            val = ctypes.create_string_buffer(temp_size)

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

            if is_string_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 unflatten_channel_string(val.value.decode('ascii'))