Am I missing something obvious? I can't find RS232 codes/commands to pass the numbers 0-9 to the Denon AVR 3313ci. Someone told me that that could only be done by IR. That makes no sense. The custom installers choice of RS232 can't be used to input numbers to change radio channels for instance! Please tell me this is not right. There have to be RS232 codes/commands for these?

Thanks for any enlightenment.

Denon AVRs dont work that way. They have specific commands for operations like tuning the FM band.

For example sending

TFAN008750<CR>

should get you

87.50 MHz on the FM band.

The TF is for "tune frequency", the AN is for ??? then you have 6 digits for the frequency.

You can also have TFANUP and TFANDOWN.

The documentation is out there but sometimes hard to find.

m.denon.fr/DocumentMaster/FR/AVR3313CI_PROTOCOL_V01.pdf

Thanks so much for this valuable information. I have searched and searched for just such an answer and finally had to break down and ask. I really appreciate it.