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Old July 23rd, 2006   #4
sblair
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John,

Have you actually seen this occur? It's not a scenario that has ever been witnessed to my knowledge yet. I have a really hard time believing it can occur given that not only does the Encoding have to match but also there is a Checksum involved. So it would align just right that when decoded not only the UID comes out as a valid UID, but it would have to match the Checksum for the packet as well! I think I have better odds at winning the lottery than getting that situation to occur if I wanted to.

You can't expect Muted devices to ignore responding to the Mute command. For one, the standard isn't written that way. Second, the expectation throughout the standard is that whenever you are communicating with a device directly is that you get some type of a response back. It is possible that some controllers may even use the Mute command as a simple heartbeat to make sure the device is still on the network. (This isn't encouraged, but it is something that people have talked about in the past).

The scenario that you discuss can be handled if you see it as a real issue. After making X number of attempts at muting the device and it continues to respond to UNIQ_BRANCH messages, then keep Branching further. At some point you'd get to the bottom of the tree and be able to individually mute the devices.

Again, I don't see it as a real issue as long as you are verifying the checksums though to know when to discard bad packets.
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