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

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, 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 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.
• 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.