# Led Output This function block provides a simple visual indicator for boolean signals. Use it to quickly check whether a condition in your scenario is TRUE, FALSE, or undefined. ## đŸ“Ĩ Inputs `Boolean` This input socket accepts a boolean signal to drive the LED indicator. Connect any logic or condition output here. ## 📤 Outputs This function block does not have outputs. ## 🕹ī¸ Controls `led` Visual LED indicator shown on the block: * Gray — input is undefined / None. * Green — input is TRUE. * Red — input is FALSE. ## 🎨 Features * Real-time visual feedback for boolean signals. * Clear color coding for three states: undefined, TRUE, and FALSE. * Lightweight and suitable for dashboards or quick debugging. ## 📝 Usage Instructions 1. Provide a boolean signal to the `Boolean` input. 2. Observe the `led` color to understand current state: * Green for TRUE * Red for FALSE * Gray when no value is present Use this block on UI screens where immediate visual feedback is helpful. ## 📊 Evaluation When the scenario runs, the block checks the boolean value arriving at the `Boolean` socket and updates the `led` color accordingly. If no value is present, the indicator shows the undefined state. ## 💡 Tips and Tricks * For manual testing, connect a `Logic Input` to the `Boolean` socket so an operator can toggle the LED on the fly. * Combine condition checks before the LED using logic blocks such as `And`, `Or`, and `Not` to visualize combined conditions. * Use comparison blocks like `Equals`, `Greater`, or `Smaller` to convert numeric measurements into boolean signals for the LED. * Use edge detectors such as `Rising Edge` or `Edge Rising` to show event pulses instead of continuous states. * Add temporal behavior with `Delay Step`, `ON Delay`, or `OFF Delay` if you want the LED to respond only after a sustained condition. * Use `Set - Reset` to latch a condition and keep the LED on until explicitly reset. * Integrate with data or communication blocks upstream (for example, use `Data Write Local` / `Data Write Global` or `MQTT Publish` on the logic feeding this block) to reflect remote or network-driven states locally. ## 🛠ī¸ Troubleshooting * LED stays gray: Check that the previous block is producing a boolean value. Consider using `Is None` or a simple `Logic Input` to test the path. * LED always red/green but condition seems wrong: Verify the upstream logic (comparisons, merges) with intermediate indicators or debug blocks before connecting to the LED. * Need persistent indicator for transient events: Use `Set - Reset` or an edge-to-latch pattern so a short pulse becomes a sustained visual state. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.augelab.com/function-blocks/input-output/outputs-exports/led-output.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.