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• Use objects for brightness adjustment
There is the option of carrying out a brightness adjustment for daylight and artificial light via the brightness detection application with the aid of the following
three objects:
(a) Brightness adjustment (daylight)
(b) Brightness adjustment (output 1)
(c) Brightness adjustment (output 2)
In the event that artificial light and daylight are perceived similarly by the sensor, or the movement detector application is used exclusively, only the absolute
brightness value need be corrected. For this the brightness value can be sent via the
brightness adjustment
object
(daylight)
, which is to be displayed by
the actual brightness measured by the device. This is then used to internally calculate a correcting factor, which will then be used for scaling / adjusting the
internally measured brightness. This adjustment is sufficient for the movement detector application. For constant light controller and switch further step may
be necessary, which are described in the following.
For the event that daylight and artificial light must be corrected separately, the following procedure is recommended:
(a) Daylight adjustment
- Carry out the measurement during sufficient daylight (> 1/2 * Setpoint)
- Switch of the artificial light
- Carry out the measurement of brightness at a defined location with a luxmeter - for example, lying down at the workplace with a view toward the ceiling
- and wait until the light is close to being constant.
Send the value to the device via the brightness adjustment (daylight) object. As little time as possible should pass between measuring and sending, to
keep the probability of a change in light conditions at a minimum.
(b) Adjustment for channel 1
- Darken the room
- Switch on channel 1 (max. brightness) and wait until the brightness is virtually constant.
- Measure the brightness with the luxmeter as previously. Send the value to the device via the "Brightness adjustment" object (output 1).
(c) Adjustment for channel 2
Repeat measurement (b) for channel 2. Switch off channel 1.
To complete the adjustment for the constant light controller, a further step is required during which the characteristic of the connected lamp is automatically
measured in dependence of the output value of the controller.
To be able to carry out the brightness calibration, the device must have been already programmed in such a way that aside from the "Start brightness calibra-
tion" object, also the output object(s) is/are connected with the corresponding actuators. Also the actuators should be programmed in such a way that the
values received are set immediately, to ensure that the calibration process runs properly.
Here too, as in item (b), the room is to be darkened, to minimize the effect of changing daylight conditions during the measurement. If this is not possible, the
adjustment should be carried out in the dark or at night. To obtain excellent results, the lamps should be turned on prior to the calibration. The calibration
can start when the measured brightness is constant, i.e. the heat-up of the lamps has been completed.
The process of calibration now proceeds as follows:
1. Brightness calibration is started by sending a "1" to the
Brightness calibration
object
(in the constant light application under extended parameters)
.
2. The lamps are switched on at 100%. Then comes a waiting period of 60 seconds for the lamps to warm up and reach their full brightness. Then the
brightness is checked to see how much it has changed since the last measurement. If the change drops below a certain percentage in comparison to
the measured value, it is assumed that the brightness is stable and the actual calibration can begin. Otherwise a new measurement is carried out after a
certain time to again determine the percentage of change. This process is repeated until a stable brightness value has been reached. However, only up
to a maximum of ten times.
3. Then the output values are reduced separately into steps of 10% and the corresponding brightness is determined for each value; and here, too, a waiting
period is necessary until the brightness values have become stable:
• A1: 100%
A2: 100%
• A1: 100%
A2: 90%
• A1: 90%
A2: 90%
• … …
• A1: 0%
A2: 0%
4. After completion of the measurement the output characteristics are calculated and stored in the device. Then a successful measurement is confirmed in
form of a "1" on the
Start brightness calibration
object.
5. If the calibration cannot be completed within a period of 6 minutes due to unfavourable light conditions (extremely fluctuating brightness values), the
measurement is interrupted and a "0" is sent via the
Start brightness calibration
object.
Note:
The calibration can be terminated by sending a "0" via the "Start brightness calibration" object. The calibration is similar if only one output is used, but only
with the A1 output values.
Commissioning
