ABB i-bus KNX Product Manual page 97

®
ABB i-bus KNX
© 2008 ABB STOTZ-KONTAKT GmbH
Commissioning
No. Function
30, 55...
Actual value
80, 105
This object is enabled if in parameter window
function the option Light control is selected.
This object contains the current actual value of the light control (see diagram
The actual value results from one or more sensors. It can be the lowest, the largest or
the average value of the sensor value. This is parameterised in the parameter window
Light sensor.
If the output is only assigned to a Light Sensor, the actual value is equal to the sensor value.
With several sensors the calculated sensor value is used for the light control.
Telegram value: 0
...
255 = 100 %
The actual value is equal to the setpoint value in a perfectly balanced control circuit. Thus it
is possible to read the value (setpoint) which results with a desired brightness via the actual
value object. This read value can be used in ongoing operation in order to provide a new
setpoint to the output of the Light Controller on the bus via the Setpoint object.
For further information see:
Note
This object can be read and written in the ETS. It will not be sent on the bus
independent of the T flag.
31, 56,
Free
81, 106
32, 57,
Sensor value
1)
82, 107
This object is always enabled. Using this the Light Sensor can also be monitored
if the sensor is assigned to another output.
This object contains the measured values which are currently measured by the Light Sensor.
The sensor value always relates to the Light Sensor which is connected to Input X. This is
also the case when the Light Sensor is assigned to another output. The sensor value can be
sent on the bus via a read request. In this way a direct change in the brightness on the
sensor can be visualised.
The read value is an unsigned value which complies with the measured value of the sensor.
It does not comply with a direct light value, e.g. the lighting intensity or the light density.
The object Sensor value is primarily intended for analysis purposes in order to detect if the
Light Sensor brightness values are detected and correctly connected to the Light Controller.
Note
The Light Sensor features a photocell which supplies a current dependent on
the brightness level. This current is evaluated by the Light Controller.
No current will flow for the Light Controller in the event of a break in the
sensor cable, short circuit or reverse polarity. In all three cases the minimum
brightness is produced at a sensor value of 0.
It is prudent to set the T flag during the commissioning phase. In this way the sensor value
is sent on the bus for analysis purposes should it change. During normal operation it is
advisable to remove the T flag to prevent unnecessary bus loads.
33,58,
Free
83,108
1)
The numbers of the objects apply for outputs A to D.
Object name
Output X
in the parameter Select additional
X: General
= OFF
Constant lighting control properties
not assigned
Output X
not assigned
Data type Flags
1 byte (EIS6)
C, R, W
DPT 5.001
control circuit).
1 byte (EIS6)
C, R
DPT 5.001
95