Support | DALI and Probit FAQ
How to solve DALI problems in the field?
Based on 25 years of experience in DALI qualification, we created a structured DALI FAQ approach to tackle any DALI problem you encounter in the field. We suggest a three-step approach for any issue:
1. Check the basics
2. Dig deeper
3. Ask the expert
Should none of the answers help, please feel free to contact us at support@lichtvision-engineering.com.
Q: I installed all DALI devices, but nothing is happing. How can I control my DALI lights?
A: Potential issue: Missing or too low DALI bus power supply.
1. Check the basics
Use a voltmeter and measure the DALI voltage. It should typically be 16 V but at least 12 V. Too long cables and / or too many DALI devices can be a reason for a too-low voltage. If there is no DALI voltage, check if there is a DALI bus power supply or if your DALI controller comes with a DALI power supply.
2. Dig deeper
If you measure a correct DALI voltage, use a USB-DALI interface to connect your PC (e.g. https://www.lunatone.com/en/product/dali-2-usb/) and use a DALI cockpit to send DALI Broadcast Commands (All On, All Off). Please check, which DALI devices react. Check the wiring of the ones not reacting.
3. Ask the expert
Use a DALI analytics tool for an in-depth analysis, e.g. ProbitSite.The ProbitSite comes with a bus power supply and can make all connected lights blink. Then you can find the ones not reacting. Additionally, you find an individual report per connected device. You can download the results from the ProbitSite and send it to an expert for further investigation.
Q: There is no reliable DALI communication although I measure a DALI voltage. How can I make my DALI bus more reliable?
A: Potential issue: Too many DALI devices (>64) or too much load (in mA) due to wrong wiring, e.g. in junction boxes.
1. Check the basics
Measure the DALI voltage using a multimeter. The voltage needs to be at least 12V.
2. Dig deeper
Disconnect a branch of DALI devices from the bus and check for improvements.
3. Ask the expert
Use a DALI analytics tool for an in-depth analysis, e.g. ProbitSite. Additionally, the ProbitSite provides an individual report per connected device. You can download the results and send it to an expert for further investigation.
Q: During the commissioning of my DALI installation not all DALI devices are found, although I can control them with broadcast commands. How can I fix DALI communication problems?
A: Potential issue: The reply of the DALI devices is not understood by the controller.
1. Check the basics
Is the problem related to a specific class of products, e.g. buttons or sensors? If so, please check if your application controllers support input devices.
2. Dig deeper
Use a USB-DALI interface to connect your PC as an alternative application controller (e.g. https://www.lunatone.com/en/product/dali-2-usb/) and try to commission the DALI installation.
3. Ask the expert
Use a DALI analytics tool for an in-depth analysis, e.g. ProbitSite, to analyze the DALI answers of all devices connected. In the report on the screen the ProbitSite shows the signal quality of every device. This will tell you, which products are causing the problem. You can download the results and send it to an expert for further investigation.
Q: A DALI device is causing trouble, but I can’t figure out the supplier because it is mounted in a luminaire. How can I find out the manufacturer of a DALI product (e.g. LED driver)?
A: Potential issue: The answer to that question is hard to get.
1. Check the basics
Contact your supplier of the DALI product.
2. Dig deeper
Contact the luminaire manufacturer mentioned on the luminaire and ask, which DALI product is used.
3. Ask the expert
Use a DALI analytics tool for an in-depth analysis, e.g. ProbitSite, to identify the installed DALI products. The ProbitSite contains a copy of the DiiA database, i.e. the list of all certified DALI products (DALI 2) and states the supplier in the report.
Q: During the DALI commissioning the controller cannot find all DALI devices. After the commissioning some units acting in pairs (identically). How do I resolve this problem?
A: Potential issue: Double DALI addresses.
1. Check the basics
Did you change or add new DALI devices? And are those part of the pairs reacting identically? Probably, the added device had previously been addressed with an address already used in your DALI installation.
2. Dig deeper
If 1. is not causing the problem, ask the supplier for the DALI certification report. The DALI certification checks the addressing process.
3. Ask the expert
Use a DALI analytics tool for an in-depth analysis, e.g. ProbitSite, to record all DALI telegrams during a scan. Send the results of the ProbitSite to an expert to check the communication.
Q: I used the ProbitSite to check my installation. The scan gives me feedback that the signal quality is poor (yellow or red). What does that mean?
A: Potential reason: Poor performance of the DALI device itself or too low dimensioned DALI power supply. Please note: a yellow or red indicator does not mean that your installation will not work. Yellow means: a transmitter may not send this, but every receiver must understand it. Red means: it is not certain that a receiver will understand this telegram.
1. Check the basics
Disconnect the DALI device from the DALI line, which shows poor signal quality. Connect the device directly to the ProbitSite (the ProbitSite provides the DALI voltage). Test if the problem persists. If it does, it most likely is a device issue. Please contact the supplier.
2. Dig deeper
If the problem persists when connecting the DALI device directly to the ProbitSite, it may be related to the power supply. Please ensure that the connected load (in mA) can be handled by the DALI power supply installed. A weak power supply can negatively impact signal quality.
3. Ask the expert
If neither approach reveals the root cause of the issue, consider contacting a specialist like Lichtvision Engineering. An oscilloscope is likely required.
ProbitSite – The DALI Multimeter
How can I view and save the scan reports on a computer?
The scan reports are stored automatically on your ProbitSite. To view and save them to a computer, please connect with the USB port and run the ProbitBench. You might need to install the Probit drivers first. For further support with downloading, installing and running the Probit drivers and the ProbitBench, please check the download section.
What do the percentage levels for DALI signal quality mean?
The ProbitSite gives the signal quality in percentages. The percentages are distributed as follows:
0%..50% Receiver Violation (it is not certain that a receiver will understand this telegram)
51%..75%. Transmitter Violation (a transmitter may not send this, but every receiver must understand it)
76%..100% Everything OK
The three values displayed (aa% – bb% – cc%) are in sequence:
The worst value (aa)
The average value (bb)
The best value (cc)
The idea behind this is that there are consistently bad signals. In this case, you have three bad values close together. However, if the signal is quite good and there are only rare glitches, the best and especially the average value would be quite high, while only the worst value would be smaller.
