Sienna has published a recommended practice proposal RP-NDI-DMX_2019_12 which details a proposal for unambiguous carriage of DMX information via NDI Metadata connections.

http://www.sienna-tv.com/ndi/dmxoverndi.html

This mechanism is already implemented in Sienna's ArtnetDMX Interface module in the NDI Processing Engine which interfaces Artnet to DMX devices.
There is also an NDI-DMX send test (along with NDI-MIDI, and NDI-GPI send tests) in the Sienna NDI Signal Generator for macOS.

https://twitter.com/NDI_Cloud/status...99460671479808

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