#閾値によって判断する

センサーからの値など、ある値を超えた際にだけ後続の処理を行わせたい場合があります。
Node-REDのフローをコピーする方法を参照して、下記のフローをコピペします。

閾値によって判断する

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「1」や「-1」ではmsgが伝搬されず後続のノードが実行されないことを確認します。
「5」や「-5」では後続のノードが実行されます。
「閾値判断」functionノードのjsは以下の通りです。

閾値によって判断する

if ( Math.abs(msg.payload) < 3 ) {
    msg = "";
}
return msg;