I have a project that is using Samsung UN55TU7000 4k tv's They need to be third party controlled. RS232 is preferable. According to samsung's web site:

Newer TVs 2016 and later can accept RS-232 commands using a special dongle that is only available to custom installers. The installers can acquire these dongles from the TV retailer.

Settings must be changed in the service menu to enable the conversion from USB to RS-232. The service menu should only be accessed by professional installers.

Samsung cannot offer phone support for these types of installations. We have a compiled list of RS-232 commands and a PowerPoint presentation of basic instructions for Samsung TVs available for download. We can provide the commands but cannot offer assistance with setup.

Has anybody done this? if so what are the commands?
there is also a mention about controlling them thru the network port.

I tried talking to Samsung tech support about third party USB control, he was unfamiliar about this.