The software of old devices is programmed to respond to IR commands through their IR receivers, not through the MasterLink.
Let's say you are in a link room and you press CD on your remote. The Beolink Active will send a message to the main room Beosound to send the sound of the CD to the Masterlink.
The CD will start, but the sound will not be heard in the main room. This shows the command "Send me the CD sound" over ML is different from the "CD" command send via IR (as this command would play the CD on the main room speakers.
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