Commissioning & Scanning
Not all my DALI devices are found during commissioning, but broadcast commands work, why?
By Lichtvision Engineering · Published
Short answer
If broadcast commands work but not every device is found, the controller often isn't recognising certain device classes, typically input devices such as sensors (Part 303) or push-button couplers (Part 301). Check that your controller supports those device types. ProbitSite's SmartScan lists every device on the bus, type, address and firmware, without changing the configuration, so you can see exactly what is connected.
Why broadcast works but discovery does not
Broadcast commands reach every device at once, with no need for the controller to know which devices are present. Lights respond even if the controller has never individually discovered them. Discovery is a separate step, the controller has to enumerate each device, read its random address, assign a short address, and store device-type information. That handshake is where it usually fails.
The usual suspects: input devices
Specific device classes are often the ones missing. Sensors (Part 303, occupancy and daylight) and push-button couplers (Part 301) are the most common, followed by emergency luminaires (Part 202) and colour-control gear (Part 209, DT8). A controller, gateway, or commissioning tool that does not implement those device types will simply skip them during discovery, even though they sit on the same bus and obey broadcast. Older single-master controllers also frequently lack Part 103 multi-master coexistence, so they miss any device that is registered to another master on the line.
Confirm what is actually on the bus
Before you suspect the wiring, confirm what hardware is really connected. ProbitSite's SmartScan reads every device on the line, including type (Part 102 control gear vs. Part 103 control devices), short address, random address, GTIN and firmware version, without altering the configuration. With that list in hand you can compare against the design and see immediately which devices exist, which your controller is missing, and which device types are unsupported.
What to do next
If devices are physically present but your controller cannot see them, the fix is usually a controller firmware update, a different gateway, or, for input devices, a separate application controller that supports Part 301/303. Re-running discovery after that, with a clean SmartScan as the reference, normally resolves the missing-device count in one pass.
Diagnose DALI issues like this in seconds
ProbitSite is the DALI-2 certified handheld multimeter built for exactly this kind of on-site fault finding.