Colour control

Specifying the colour space

The gateway can be used to control the light colour when using DALI operating devices of device type "DT8 - Colour Control". The gateway enables flexible colour control in the colour spaces "RGB", "RGBW", "HSV" or "HSVW". In the RGB colour spaces, the colours "red", "green", "blue" and optionally also "white" can be directly controlled by combined or separate communication objects according to the KNX specification. In the HSV colour spaces, separate objects are always available for controlling the light colour by absolute values for hue (H), saturation (S) and brightness value (V) and optionally also for the white value (W).

DALI operating devices of the "DT8 - Colour Control" device type must at least correspond to the "Colour Control RGB" colour type. The colour type "white" [W] is additionally required in the colour space "RGBW" or "HSVW". The extended DALI colour types "AF" (Amber [A], Freecolour [F]) can be assigned to a group or single device in the course of DALI commissioning, but are not supported by the gateway.

The colour space to be used for group or single device control is defined by the parameter of the same name on the parameter pages "DALI system... -> Configuration groups -> [x] Group name -> Colour" or "DALI system... -> Configuration single devices -> [x] Device name -> Colour". Whether the colour space is available with or without the white value "W" is set in the general configuration of the groups and single devices under "DALI system... -> Configuration groups" or "DALI system... -> Configuration Single Devices".

1. Set the parameter to "RGB combined" or "RGBW combined".

• The colours "red", "green", "blue" and optionally also "white" are individually controlled by absolute values or a common object. This object has a size of 3 bytes in the colour space "RGB" (DPT 232.600) and 6 bytes in the colour space "RGBW" (DPT 251.600). The default colours transmitted by the 6-byte value are evaluated only if the corresponding 1-bit enable flags (bits 0...3) are "1" in the data value. With "0", the respective colour is ignored.
  In addition to the default object, another object of the same data type is available for the status indication of the currently set colour.

• The gateway transmits the RGBW colours received from the KNX directly to the DALI side. The parameter "On receipt of a colour value" defines whether the value is jumped to directly or alternatively a dimming process is carried out by means of time-controlled fading.

1. Set the parameter to "HSV" or "HSVW".

• The colours "red", "green" and "blue" are individually controlled in the HSV colour space as an absolute value specification by separate 1-byte objects for the hue (H / DPT 5.003 / 0...360°), the saturation (S / DPT 5.001 / 0...100%) and the brightness value (V / DPT 5.001 / 0...100%). The white value is optionally specified by a separate 1-byte object (DPT 5.001 / 0...100%).

• The gateway calculates the RGB values used in the DALI from the specified HSV values. In addition to the default objects, four other objects of the same data types are available for the status indication of the colour currently set.

Setting the switch-on colour

The switch-on colour can be set separately for each DALI group and each single device.

A memory value is also then saved internally by a switch-off telegram if the bus-controlled switch-off is overridden, for example, by a disable or forced position function or by a manual operation. In this case, the internally tracked colour value is saved as memory value.

The colour to be set by switching on is either dimmed in the configured dimming time or is jumped to directly depending on the configured dimming behaviour (absolute dimming). The dimming characteristic curve for colour changes is always linear.

Dimming characteristic and dimming speeds

When controlling groups or single devices, the colour can be influenced by an absolute dimming process (value specification). In the "RGB individually" or "RGBW individually" colour space, it is also possible to relatively dim a colour or the white value with a 4-bit telegram (DPT 3.007).

• Absolute dimming:
  Absolute dimming is triggered by the specification of a colour or white value. Depending on the configured colour space, these values can be determined either by the RGB communication objects present in each single device "Colour ... (Value) - Setting" or alternatively by the HSV value objects "Hue (H)", "Saturation (S)" and "Brightness Value (V)". In addition, colour values can also be set by the scene function.
  When specifying a colour value by the objects mentioned or by a scene recall, it can be parameterised whether the value is jumped to directly or alternatively dimmed by a dimming time (Fading Time).
  An absolute dimming telegram for controlling the colour can also switch on a group or single device in the "OFF" state. Here too, it may be necessary in some applications for a switched off group or switched off device to still remain off if a new colour value is specified absolutely. The parameter "Behaviour in the switched-off state when changing the colour by absolute dimming" determines whether a DALI group or a single device in the "OFF" state is switched on by a new absolute colour dimming telegram or remains switched off.

• Relative dimming:
  Relative dimming can be triggered by the existing 4-bit communication object "Colour ... (Dimming) - Setting" for each colour or optionally also triggered by the object "White (Dimming) - Setting". The data format of these objects - as well as with relative dimming of the brightness - complies with the KNX DPT 3.007, which means that the dimming direction and relative dimming increments can be predefined in the dimming telegram or dimming procedures can also be stopped. A relative dimming process allows the colour intensity to be changed continuously.
  The dimming speed for relative dimming can be configured separately for each group and each single device and independent of the dimming speed for a brightness change.
  Just as with absolute dimming, a relative colour dimming telegram can also switch on a group or single device in the "OFF" state. In some applications, it may be necessary, however, for a switched off group or switched off device to still remain off until a relative dimming telegram of the colour is received. This is interesting when using light scenes, for instance: Several DALI groups are set to a defined colour via a light scene. Other groups are switched off by the scene. Only the colour of channels not switched off by the scene recall should be changed by dimming up afterwards. Here, it is necessary for groups or single devices not to respond to a relative dimming telegram and thus not to switch on. The parameter "Behaviour in the switched-off state when changing the colour by relative dimming" determines whether a DALI group or single device in the "OFF" state is switched on by a relative dimming telegram of the colour, or remains switched off.

The dimming characteristic curve for colour changes is always linear.

A dimming process of the colour cannot be triggered with the manual control on site at the device.

Even if colour values are instantly jumped to, the dimming procedure on DALI operating devices always takes a very short time. This dimming procedure is dependent on the system. The colour value jumped to will be dimmed to within 0.7 seconds (short fading). This time cannot be altered.

Setting dimming behaviour for absolute dimming

During a scene recall, the dimming behaviour can be configured separately.

Setting dimming time for relative dimming

The dimming time for relative dimming can be set only in the colour space "RGB individually" and "RGBW individually".

Setting dimming behaviour in OFF state for absolute dimming

An absolute colour telegram can switch on a group or single device in the "OFF" state, whereby the behaviour is set by the parameter "Behaviour in the off state when changing the colour by absolute dimming".

Usually DALI operating devices initially switch on automatically with the last active colour value after being switched on. The operating devices then immediately dim to the absolutely specified colour (jumping to: by standard fading of 0.7 s / dimming: by configured fading).

Setting dimming behaviour in OFF state for relative dimming

A relative colour dimming telegram can also switch on a group or single device in the "RGB individually" and "RGBW individually" colour space in the "OFF" state, whereby the behaviour is set by the parameter "Behaviour in the off state when changing the colour by relative dimming". The colours "red", "green", "blue" and optionally also "white" are individually controlled by separate 4-bit objects.

Usually DALI operating devices initially switch on automatically with the last active colour value after being switched on. Afterwards, the operating devices immediately dim to the predefined switch-on colour (by standard fading of 0.7 s). Only then does the relative dimming process of the colour to be dimmed start. Switching from the last active colour to the switch-on colour can initially cause rapid colour changes, which not only changes the relative colour to be dimmed.