フリー問題

問題文

A plant's emergency shutdown logic must still act correctly when the corporate network, the historian and the remote engineering workstation are all unreachable. Which design property must hold for that logic?

選択肢

1. The design must provide shared corporate directory lookup inside that control documentation.
2. The design must provide central cloud decision routing inside that control documentation.
3. The design must provide independent local actuation capability inside that control documentation.
4. The design must provide remote operator manual approval inside that control documentation.