問99
頻出度★☆☆
IoT デバイスと IoT サーバで構成され, IoT デバイスが計測した外気温を IoT サーバへ送り, IoT サーバからの指示で IoT デバイスに搭載されたモータが窓を開閉するシステムがある。このシステムにおけるアクチュエータの役割として, 適切なものはどれか。
令和2年度 ITパスポート試験 問99
テクノロジ系コンピュータ構成要素 › 入出力デバイス
This question's explanation and your answers so far.
解説
問 99
Incorrectア
Receiving the outside air temperature data is the job of the IoT server, which aggregates data. An actuator is not a device that receives and analyzes data but one that performs physical actions, so this is wrong.
Incorrectイ
Sending the instruction to open and close the window is the role of the IoT server, which handles judgment and control. An actuator is not the side that “issues” instructions but the side that receives instructions and actually moves, so this is wrong.
Incorrectウ
Converting the outside air temperature (a physical quantity) into an electrical signal is the role of a sensor (in this case a temperature sensor). An actuator does the opposite, converting an electrical signal into physical action, so this is wrong.
- エ
正解 An actuator is a device that converts an electrical signal or a control instruction into physical motion or force, thereby acting on the outside world. In this system, the thing that actually moves an object is the motor that opens and closes the window. It receives the instruction (an electrical signal) from the IoT server and turns it into rotational motion, moving the physical object that is the window. Therefore the role of the actuator is to “open and close the window,” and エ is correct.
ここがポイント
- Actuator = a device that converts an electrical signal or control instruction into physical motion (force, movement) to act on the outside world (e.g., a motor or a valve).
- Basic IoT structure: distinguish the division of roles among the sensor (physical quantity → electrical signal, for measurement), the actuator (electrical signal → physical action, for acting), and the server (receiving data, making judgments, and issuing instructions).
用語