The CFA533 will ignore any packet that is not properly structured, or that it does not recognize.
It's been a while since I worked with RS-485 (20+ years), but I recall setting up a converter for a device and setting up the address for that device. Tthe RS-485 to RS-232 converter would "listen" for it's address, and then forward the packets to the device on the other side. I'm not quite sure how this would work with a CFA533. With it's structured packets - [Command] [Data Length] [Data0][Data1]....[Datan][CRC] the converter would need to pass on the packets correctly. The device I used was very simple and did not talk back like the CFA533 family does.