KNX Basic practical exam: 3 worked ETS6 exercises

Use a compatible KNX interface, bus power supply, KNX push button, switching actuator and dimming actuator with a compatible load. A rig prepared by your centre is sufficient. Without hardware you can practise project structure and associations, but cannot verify downloads or a physical response.

Create a working project, line and room. Import the exact application programs for the rig’s devices. Give each device a distinct individual address, for example 1.1.10 for the button and 1.1.20 for the actuator. Record the hardware reference, application version and purpose of each channel. All addresses here are exercise examples.

Keep individual and group addresses distinct: the former identifies a device; the latter connects a function to its communication objects. Save/export the project before each exercise and keep your function table. Follow the centre’s instructions for the interface, KNX Secure and any project keys.

Brief. One press turns the light on; another turns it off. Status feedback should represent the actual output where the hardware supports it.

Configuration. Enable switching on the button and actuator channel. Create 0/0/1 — Light command, DPT 1.001, and link the button’s switching object to the channel’s switching object. If feedback is available, create 0/0/2 — Light status, also DPT 1.001, and link the actuator’s feedback object to the appropriate display object on the button. Command and status have different roles.

Commissioning. Check the bus connection and program individual addresses using the centre’s procedure. Download the applications and parameters after linking. Test both transitions and observe the destination address and value in the Group Monitor.

Expected result. An ON command on 0/0/1 followed by OFF changes the output. Available feedback on 0/0/2 follows its state. A command telegram alone does not prove the light works.

Mistakes to investigate. An individual address used as a group address, the wrong object or an application not downloaded. Do not change every flag at random: compare object roles with the manual.

Brief. A short press switches; a long press increases or decreases brightness. An absolute 50% setpoint provides an additional check.

Configuration. Enable the button’s dimming function and the dimmer channel. Keep 0/0/1 — Switching, DPT 1.001. Add 0/1/1 — Relative dimming, DPT 3.007, between the relative dimming objects. Add 0/1/2 — Brightness value, DPT 5.001, for an absolute setpoint if supported by the application. A 4-bit object and a 1-byte object are not interchangeable: data length and meaning must match.

Commissioning. Download both affected devices. Test short presses, long presses in both directions and release. For this exercise, configure stop-on-release if the button supports it. Then use the Group Monitor to send an absolute 50% value with the correct DPT.

Expected result. Switching, relative dimming and the absolute setpoint each work through their own object. A 50% setpoint is a command value; it does not guarantee 50% measured luminous output. Load behaviour depends on the hardware.

Mistakes to investigate. Incompatible DPTs, a disabled dimming object, an absolute setpoint linked to the relative object or an omitted download. If the telegram is correct but the load behaves badly, check settings and compatibility with the trainer using the manual.

Brief. The button appears to work, but the light stays off. On a copy of the working exercise 1 project, remove only the 0/0/1 association from the actuator’s switching object, then download that device. This training fault has a known cause; it does not cover every possible failure.

Step 1 — Observe before changing. Start the Group Monitor and press the button. Record the time, source address, destination address, service type and value. For this fault, the button does send to 0/0/1. If no telegram appears, first check the interface, connection, button and download before blaming the actuator.

Step 2 — Compare project and rig. Check that the hardware’s individual address matches the project. Inspect the switching object: its 0/0/1 association is missing. A telegram visible at the interface does not prove the expected channel received and processed it.

Step 3 — Fix one cause. Restore the association, download the actuator and repeat exactly the same ON/OFF test. Check the output and available feedback.

Expected result. The light responds after the association is restored and downloaded. Record symptom, evidence, change and result. If the fix fails, continue checking configuration, bus path and hardware with the trainer instead of making many changes at once.

• Readable project: name rooms, devices, channels and group addresses by function.
• Compatible objects: check DPTs and data lengths; distinguish command from feedback.
• Commissioning: distinct individual addresses; download affected devices after changes.
• Functional checks: test ON/OFF, dimming and stopping; keep telegram records or notes with the project.
• Explain the diagnosis: one hypothesis, one observation, one fix, another test.

Ask your trainer for a different brief and repeat without copying addresses. Adapting the project matters more than memorising a menu path. Continue with the 14-day preparation programme and worked theory questions.