Two DMX over Ethernet devices are supported as DMX output: ArtNet and sACN/E1.31.
The ArtNet bridge can only be operated in unicast mode (broadcast mode is not supported as the specification recommends using it if more than 40 nodes are connected, which is unlikely in the case of a smarthome).
The sACN bridge supports both, unicast and multicast.
The second one is the tunable white thing, it allows to control the color temperature of lamps with seperate DMX channels for cool white and warm white.
It can contain one or more DMX channels and binds to Switch items only.
If the thing receives an ON command all running fades in all channels are either suspended (if resumeAfter is set to true) or cleared and replaced with the fades defined in this thing.
An OFF command stops the fades and either restores the previously suspended fades (if resumeAfter is set to true) or just holds the current values.
If any of the DMX channels in a chaser receives a command from another thing, the status of the chaser is updated to OFF.
Since the brightness perception of the human eye is not linear, all bridges support `applycurve`, a list of channels `applycurve` that have a CIE 1931 lightness correction (cf. [Poynton, C.A.: “Gamma” and its Disguises: The Nonlinear Mappings of Intensity in Perception, CRTs, Film and Video, SMPTE Journal Dec. 1993, pp. 1099 - 1108](https://www.poynton.com/PDFs/SMPTE93_Gamma.pdf)) applied.
This list follows the format of the thing channel definition.
There are two more configuration values that usually don't need to be touched.
The address and port of the sender will be automatically selected by the kernel, if they need to be set to a fixed value, this can be done with `localaddress`.
There are some more configuration values that usually don't need to be touched.
The address and port of the sender will be automatically selected by the kernel, if they need to be set to a fixed value, this can be done with `localaddress`.
The `steps` value is a list of steps that shall be run by the chaser.
The format of a single step is `fadetime:value,value2, ...:holdtime`, two or more steps are concatenated by `step1|step2|...`.
In textual configuration line-breaks, spaces and tabs are allowed for readability.
The fadetime is used for fading from the current value to the new value.
In contrast to the dimmer thing, this is an absolute value.
The hold time defines how long this step shall wait before advancing to the next step.
A value of -1 is used to hold forever.
Both times are in ms.
An optional configuration value is `resumeafter`.
It defaults to false but if set to true, the original state of the channel (including running fades) will be suspended until the chaser receives an OFF command.
### Dimmer Thing (`dimmer`)
There is one mandatory configuration value for a dimmer thing.
It is the `dmxid`, a list of DMX channels that are associated with this thing.
They default to 255 (equals 100%) and 0 (equals 0%) respectively.
This value can be set individually for all DMX channels, the format is `value1,value2, ...` with values from 0 to 255.
If less values than DMX channels are defined, the values will be re-used from the beginning (i.e. if two values are defined, value1 will be used for channel1, channel3, ... and value2 will be used for channel2, channel4, ...).
Related is the `dimtime` option: it defines the time in ms from 0-100% if incremental dimming (`INCREASE`/`DECREASE`) is used.
For convenient use `dimtime` usually is set to a larger value than `fadetime`.
Typical values are 500-1000 ms for `fadetime` and 2000-5000 ms for `dimtime`.
Advanced options are the `turnonvalue`and the `turnoffvalue`.
They default to 255 (equals 100%) and 0 (equals 0%) respectively.
This value can be set individually for all DMX channels, the format is `value1,value2, ...` with values from 0 to 255.
If less values than DMX channels are defined, the values will be re-used from the beginning (i.e. if two values are defined, value1 will be used for channel1, channel3, ... and value2 will be used for channel2, channel4, ...).
For color things the number of values has to be a multiple of three.
Additionally a channel for cool and warm white brightness as well as color temperature (`0` being the coolest, `100` being the warmest) will be provided.
If less values than DMX channels are defined, the values will be re-used from the beginning (i.e. if two values are defined, value1 will be used for channel1, channel3, ... and value2 will be used for channel2, channel4, ...).
This example defines a sACN/E1.31 bridge in unicast mode which transmits universe 2 and three things: a three channel dimmer used to control a RGB light, which takes 1s to fade from one color to another and 10s from 0-100% on incremental dim commands, a single channel dimmer which will turn on only to 90% if it receives an ON command and does not fully switch off (to 10%) if it receives an OFF command and chaser which changes the colors like a traffic light.
