Bravia series TVs can be controlled via IP.

However, after deploying a few dozen of them like this, we've been seeing stability problems. The TVs stop responding via IP, and need a hard power cycle before they will come back online. Depending on what's feeding it's network port, other shenanigans may be required as well. Simple IP control must be turned on in the network menu. The IP API is different from the RS-232 API, BTW, just to have fun with acronyms.

When dealing with RS-232, you've got to have the TV powered up, and send it a "POWER INIT" code at least once, ($8C,$00,$01,$02,$01,$90) before it will start responding to anything once it turns off. Otherwise, you could end up with it on, test it for things like volume control, and it would all work. Then you turn it off, and ... it goes dead.

And yeah don't forget to turn on the Serial control in the menu for RS-232. I just spent way too long trying everything else before realizing that setting is in the menu.