RDM thru DMX 1-2-3-4 outputs

Is it possible to work with RDM through DMX outputs 1 ---- 4?

Which hardware?

It is possible, but Your hardware needs to be able to run RDM. For example - all Onyx units and new dongles are compatible with RDM. As it goes for Artnet-DMX gates, not all are running artnet correctly. I get mixed results with different brands. Netron, I can tell, runs good with RDM.

That is only through the gateway Artnet to DMX ,not directly.?

eNode4 works like this gateway?

Yep, but on eNode 4 RDM will have problems - tested - I get only bad results.