Thank you for this response.

I have the TSU7500. It's my third Pronto unit; my first was the TSU6000 and my second was the TSU7000. I have always assumed that IR codes would be available for every command that my hardware needed.

I just purchased the Sony BDP-CX7000ES (because I wanted 4K quality). My previous DVD/CD carousel was the Sony DVP-CX875P which held 200 discs. I had no problem programming the Pronto Pro once I found the IR codes for 'DISC SELECT' and 'DISC ENTER'. Worked like a charm.

Your solution is totally different from what I expected. To be honest, I am really ignorant of "RS-232" or "IP" control. I don't know what that means. I read through your approach and it seems so complex.

Are you saying that there are no IR codes for 'DISC SELECT' and 'DISC ENTER' on the Sony BDP-CX7000ES?

I just find that so hard to believe.

Thank you again for trying to help me.