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Old May 18th, 2010   #22
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Join Date: Aug 2008
Posts: 369

Originally Posted by berntd View Post
But where in the response does the responder set which subdevice is actualluy responding? Is it just byte 3/4 ?
Byte 3/4 counting from where?

Looking at table 6-6 in the standard, the sub-device goes in slots 18 and 19. It's after the Message Count and before the Command Class.

For the GET QM request, slots 18:19 would be 0x0000.

If subdevice 9 had a new DMX address, slots 18:19 in the response would be 0x0009.

For most RDM packets, the response's Sub-Device Field will match the request's sub-device, but this is one case where they won't match.
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