Any unshielded 2-core wire can be used. However, a suitable diameter must be used according to the length. Typically, 1.5mm mains rated twin is used. This will allow the DALI Line to be extended to its maximum length if required in the future.
Another option is 5-core soft cabling. The 5-core cable consists of 3 wires for 240V mains (Active, Neutral and Earth) and 2 for DALI. From a hardwired starter socket, 5-core premade leads can be connected from ballast to ballast. This method allows greater flexibility when future changes are required.