node-red-contrib-knx-ultimate/tutorial/knxUltimateAutoResponder.md

Control your KNX and KNX Secure intallation via Node-Red! A bunch of KNX nodes, with integrated Philips HUE control and ETS group address importer. Easy to use and highly configurable.

# knxUltimateAutoResponder Node – Tutorial Outline

## 1. Intro (0:00)
- "Welcome back! Today we’ll configure the `knxUltimateAutoResponder`, the companion node that automatically answers KNX group read requests with default values."
- "Perfect for virtual sensors, gateways, or integrations that expect the KNX bus to always respond."

## 2. What It Does (0:25)
- "Listens to the KNX gateway selected in the config node and replies instantly when specific group addresses receive a `GroupValue_Read`."
- "Useful when you have virtual devices (cameras, alarms, cloud sensors) with no physical actuator to answer reads."

## 3. Inputs & Outputs (0:45)
- "No inputs and no outputs—the node works in the background as a service."
- "All configuration happens in the JSON rule list; once deployed it intercepts reads and sends the matching defaults."

## 4. Core Configuration (1:05)
- **Gateway**: link to the `knxUltimate-config` node that maintains your tunnel credentials.
- **Name**: optional friendly label.
- **Respond To JSON**: list of rules describing the group addresses and fallback values. The default example shows:
  - A single GA with `default: true`.
  - A GA range (`3/1/1..22`) with datapoint `1.001` and default `false`.
  - Another range using `5.001` with a numeric fallback.
  - A single GA returning a text default.

## 5. Rule Syntax (1:45)
- "Each object accepts the fields: `note` (optional), `ga` (single GA or range), `dpt` (optional datapoint), and `default` (the value that will be sent when the bus asks for it)."
- "Ranges use the `start..end` syntax. The node expands them automatically."
- "If no datapoint is provided, the responder inherits the one configured in the KNX devices listening to that GA."

## 6. Practical Tips (2:20)
- "Keep the rule list organised with comments via the `note` field; it’s useful when you return months later."
- "Use the typed input editor in JSON mode to format the array cleanly."
- "When responding with text, set the datapoint to `16.001` so length and encoding match."
- "For booleans or percentage defaults, pick the appropriate DPT to avoid decode errors downstream."

## 7. Testing Workflow (2:50)
- "Deploy, then issue a `GroupValue_Read` using a `knxUltimate` node or ETS; the responder injects the default telegram immediately."
- "Use the Node-RED debug sidebar or the ETS monitor to verify the automatic reply."

## 8. Best Practices (3:10)
- "Place comments in the JSON to document why each virtual device exists."
- "Group related virtual devices in the same node; spin up multiple auto responders if you want different defaults per room."
- "Review the list whenever you change your ETS project so ranges always match the KNX design."

## 9. Wrap-Up & CTA (3:30)
- "We linked the node to the gateway, configured the JSON rule list, and discussed how to verify the automatic replies."
- "Hit like and subscribe if virtual KNX devices are part of your automation stack—more node tutorials coming up!"