SPECTRA TUNE HCL
Human Centric Lighting for Researchers
12
The installer must wire the installation with a single twisted pair bus cable to enable
communication between the LIGHT HUB and the network of SPECTRA TUNE HCL
downlights.
NOTE
: Installation of the luminaires and the equipment MUST be done only by qualified
staff, taking the security measures collected by the regulation in force at the installation site.
COMMUNICATIONS BUS
To build the communication bus, a shielded twisted pair wire should be used. It is
recommended to use any range of wires between AWG-24 to AWG-18 with a characteristic
impedance of 120 Ω. Ideally, the wires should be of different colors to avoid confusion when
connecting all luminaires to the bus. Each luminaire should be connected to the twisted pair
bus as show in Figure 11. Even though in some circumstances may not be necessary, it is
highly recommended to always use an end-of-
line (EOL) 120 Ohm (Ω) resistor.
An example of the communication bus layout is shown in Figure 12 for a typical
configuration
Figure 11. Details of a communication bus RS485. A pair of twisted wired must be
connected to the LIGHT HUB (labeled A, B)
Figure 12. Example of the bus layout
