DALI design - limits

When preparing the design make a sure to create an overview.

  • Prepare a simple schematic diagram or a list of devices for the system in each area/room.

  • Based on the design limits fill each port with devices. Having rooms close toogether in one bus makes the installation easier.

  • For each controler create a list of devices: lminaires, emergency, sensors and panels. Assign a naming system to devices (we suggest the one shown below).

You can't get a good quotation without a good design.

E2D design guidelines:

  1. DALI bus length

  2. Maximum current value limit

  3. Address number limit

  4. Number of sensors and panels on one bus

  5. DALI bus topology

DALI bus length

The maximum distance between the last device and the Vertex controller is 300 m.

Vertex has 3 DALI ports and each port has 2 inputs, so put Vertex in the middle of the device's line to double the distance between them to 600 m.

Maximum current value limit

Up to 64 DALI devices can be connected to each bus (55 per bus is the maximum we recommend).

For each bus the total current value must be not exceeded.

For example, the project includes 42 luminaires and 8 sensors on one bus. The permissible current for the Vertex 3 is 230 mA* per port. The current consumption for the luminaires is 2 mA, and for the selected sensors, the maximum current consumption is 18 mA. The total power consumption of these devices is 228 mA. It is less than the permissible limit on the bus, so it’s ok.

*The total current value for the Vertex 3 is 230 mA per bus, but for the Vertex 2, it's 180 mA.

DALI address limit

64 DALI devices can be connected to each DALI bus. We recomend 55 devices per bus.

Usually, one DALI device takes up 1 address. However, there are some luminaires that use more than one DALI address and other devices such as relay units that can use 4 or even 8 addresses. Information about the total number of DALI adresses can be found in the device datasheet.

Count the addresses, not the individual devices!

Number of sensors and panels on one bus

Sensors and panels have a different limit. Up to 8 of those devices can be connected per one DALI bus. This restriction does not apply to luminaires. There can be both sensors and panels on one bus, and, of course, luminaires. Remember that Vertex controller has 3 DALI ports, so a total of 24 sensors and panels per one Vertex can be connected. Do not exceed the recommended total number of devices on one bus (55).

DALI bus topology

Remember that looping of the bus is not allowed and it will cause system failure. Use only the permitted DALI bus topologies described below.

The good bus topologies are tree, star and line.

DALI bus looping is not allowed.

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