SDLx

The luminance meter measurement and control unit SDLx system allows to turn the photometric magnitude (veiling luminance or L20) measured by the optical detector into four information levels as well as four relay outputs to control four different levels. The advantages offered by such a system particularly apply to road tunnels. More particularly, if combined with a power controller or with LPM/C system for LED control, SDLx system enables to control the tunnel lighting as requested by Standard CIE 88/2004, by simply connecting the control message to the input of the power controller, while the digital outputs are connected to the contactors of the circuits.

The SDLx system consists in two or three elements:

• One or two external veiling or L20 luminance meter made of waterproof polypropylene, UV resistant with a protection degree IP65. The veil luminance meter is to be placed at the stopping distance from the tunnel entrance, according to CIE 88/04 requirements.
• The internal (optional) sensor to measure lighting level inside the tunnel (luxmeter), alternative to the second external sensor.
• SDLx control module, made of self-extinguishing technopolymer with protection degree IP20, fittable to DIN rails, houses the electronic circuits and microprocessor logics. The front part of the module holds LEDs.In order to fully operate the system, DIM module has to be added, which has a keyboard to set parameters and a backlighted display to read the measurements. The control module may either be installed in an electric control panel or in a SEC STPi power controller. All the functional parameters of the unit can be set or changed by means of the programming keypad.

Communication between the sensors and the control module is by means of a two/three/ five-wire cable. Combining a SDLx system to the power controllers of the Reverberi range equipped with DIM module or Opera system, results in the possibility to adapt tunnels indoor illuminance on the basis of outdoor luminance through the control signal, each settable in accordance with the specific exigencies and differentiated for each power controller connected. 

Up to 4 power controllers may be connected to SDLx system, controlling either the step circuits and the permanent circuit by dimming the illuminance level from 100% to about 40% in a continuous mode. The four relay outputs permit as well to control the switch ON/OFF phases of the step circuits by dimming the illuminance level from 40% down to the minimum value ensured by the permanent circuit. Other applications are however offered by the SDLx unit even if separate from the SEC STPi power controllers, namely as pilot unit for the switching ON/OFF of groups of luminaires through the 4 relay outputs, each settable individually.
SDLx system allows fully programmability from remote stations, for example through wired bus or modem GSM, and can exchange information with DIM module. When equipped with remote control communication it is possible to download measurements, parameters and alarms stored in the memory, it is possible to display measurements made by light meters and status of digital outputs. In case of fault or in case of anomalies, it is possible to call one or two Control Centers to signal the condition.

Control module can fully manage up to two light meters, for example one outside the tunnel, the other inside. The values measured can be used to keep under control the K ratio between internal and external illuminance, to keep into consideration the decay of the luminous flux due to age and dirtiness of lamps.

It is possible to verify the difference between the illuminance expected and the one measured, and correlate with the voltage to lamps through an internal algorithm. If the difference exceeds a threshold, due to dirty or to lamps switched off, or to fault in the sensor, then a limited operative condition is activated, and the control is given only to the external sensor. SDLx controls as well the signal coming from the sensors: if they are steady for a long period, a failure condition is expected and a hourly control is activated. In this case, the 4 digital and the control signal are submitted to the control of the program set in the SDLx, which is a hourly cycle. In case of total failure of SDLx system, a relay output is activated. This signal can be used to control the lights through an astronomical clock, for example the one present in DIM module.