We've used a few paid for providers of digital signage solutions.
The first major one had customizable rs232 commands which would allow us to put in rs-232 codes in different formats depending on what the tv will accept.
The second major one is a better platform but actually a step back on the rs232 front. We basically have to contact the company get them to add a code individually to our account and even then it is limited to only power on and off.
Was great being able to do everything ourselves and even if the format of the code was wrong we could do trial and error without waiting for a third party to add a code or take up their time. This is an essential piece to our digital signage system as we cannot rely on locations to make sure their tv's are on or that if the power went out the internal tv timer is reset properly.
