Idk where to really ask this. I figured some ppl here might now about rs232 and visca. 
I have a old school DIY camera controller that looks like it is all hardwired using basic switches that control zoom, brightness, and focus on the camera. It uses Sony FCB-ix block camera. The old camera works plug and play but the new one I bought does not. They are the same models as the origonal one. None of the functions with the DIY controller work with the new one, I only get video feed. So I'm guessing the new one needs programmed using visca? But idk how to do that. I've read the manuals and I see where it says to set values and addresses and stuff but that's gibberish to me. I dont even know how to hook it up to a computer to do so. Or do I need a special controller or interface board to set those values and addresses? 

I traced all the wiring and the only communication wire being used goes to the RxD in RS-232c pin on the camera. Idk how they got zoom and all that to work through just one wire. 

I work for a company that inspects gas tanks at gas stations and this is what they use to do that. I know it needs to just be upgraded but trust me when I say they wont. They dont want to spend the money.