---
title: "Link’nX access control: KNX scenes at the start and end of access"
description: "Send a KNX scene when a Link’nX access starts and ends: group address, DPT, value and an end scene lead time from 0 to 60 minutes."
canonical: https://wiki.can-nx.com/en/guides/link-accesscontrol-scenes/
language: en
product: Link’nX
audience:
  - administrateur
  - installateur
context: "Link’nX web: Access Control section, scene commands of a declared access point"
---

# Link’nX access control: KNX scenes at the start and end of access

Context: Link’nX web: Access Control section, scene commands of a declared access point

An access point declared in Link’nX can send one KNX command when access starts and another when it ends: group address, DPT and value. A lead time lets you request the end scene a few minutes before the end of each booking.

Intended for the installer or administrator in charge of access control. A scene can control equipment in the installation: its settings must be validated for the installation.

## Before you start

- The access point is [declared in Link’nX](https://wiki.can-nx.com/en/guides/link-accesscontrol-device/), or you are declaring it.
- For each command planned at the start and end of access: the KNX address, the DPT and the value.

## Fill in the scene commands

1. In Link’nX, open **Devices → Security & Access → Access Control**, then the **Edit** pencil of the relevant access point. For a creation, start from the [hardware declaration](https://wiki.can-nx.com/en/guides/link-accesscontrol-device/) form.
2. Under **Scene commands (optional)**, fill in only the necessary commands:

| Block | Fields to complete |
| --- | --- |
| **Scene Start Address** | Group address, **DPT** and **Value** of the command associated with the start of access. |
| **Scene Reset Address** | Group address, **DPT** and **Value** of the end command. |

3. As soon as a scene address is filled in, its **Value** must be filled in too. For a text DPT **16.x**, the value is text; for the other DPTs, it must be numeric. **0 is a valid value**, different from an empty field. Use the DPT actually planned for the command.
4. To choose when the end scene runs, fill in the delay described in the next section.
5. Click **Update** for an existing declaration, or **Save** for a creation. Wait for the success message and the return to the list.

## Set the end scene delay

Under **End scene lead time**, the **Delay** field is in **min**. It accepts a whole number from **0 to 60**, or an empty field.

| Entry | Configured behavior |
| --- | --- |
| **5**, fictitious example | Requests the end scene five minutes before the end of each booking, when a reset scene is configured. |
| **0** | Requests the end scene at the booking’s end time. Zero is an explicitly configured delay. |
| **Empty** | The end scene follows the deactivation of the code. The help text specifies: for API bookings, one minute before the end; for administrator bookings, at the end. |

This delay only sets the end scene: the access code stays valid until its normal deactivation. It does not replace configuring the **Scene Reset Address**, its **DPT** and its **Value**.

To remove an explicit delay, clear the **Delay** field, validate with **Update**, then reopen the access point to check that the field is empty. Do not enter zero if you want to return to the behavior of an empty field.

## Check the result

1. Reopen the same access point and reread the addresses, DPTs, values and delay that were kept.
2. Watch the controlled equipment at the start and end of a booking: this test confirms that the scenes run, which saving alone does not guarantee.

## Troubleshooting

- **Whole number between 0 and 60 minutes**: enter a whole number in this range, or leave the delay empty, depending on the goal. A negative, decimal or greater-than-60 value is refused.
- Saving does not go through: check the hardware’s required settings, then the value of each scene whose address is filled in. An empty field does not send zero.
- The code stops working earlier than expected: do not change the scene delay to try to extend its validity. Check the period and the information of the booking with the [access troubleshooting guide](https://wiki.can-nx.com/en/guides/ac-troubleshoot/).
- The expected scene does not occur: reread the access point, the saved scene command and the delay, then the context of the booking. Do not repeat KNX writes at random.

## Contact support

If the scene still does not occur after these checks, write to support@can-nx.com with the scene concerned, the expected time, the booking type and the attempts made. Do not send a PIN code or a secret link.

French labels: **Commandes scène (optionnel)**, **Adresse scène démarrage**, **Adresse scène réinitialisation**, **DPT**, **Valeur**, **Délai d'anticipation du scénario de fin**, then **Délai** and **min**. **Mettre à jour** saves a change, **Sauvegarder** a creation.