DMX_BLOCK_ADDRESS (Set)

[hamish]

Originally Posted by ericthegeek

The behavior you want is to set the root's fan speed slot to address 11, and then address the 24 dimmers from 12 to 35 when you receive the Block Address PID?.

The problem domain is a little less complicated than that. The Root device has no real DMX slots, just virtual ones that represent the sub-devices, but only when the sub devices are contiguous. So:

When contiguous, Root DMX address = sub device DMX address and root foot print = sum total of sub device slots.

For example, if there are 10 sub-devices from 13 to 22, contigouosly adrressed. Root DEVICE_INFO reports DMX Address 13, footprint of 10.

Sub device 5 address is changed from 17 to 2.
The responder is no-longer contiguously adressed.
Root DEVICE_INFO reports DMX Address FFFF, footprint of 0.

The shall rule is not explicitly violated as the DMX address is the same, the footprint has changed.

Now we set the BLOCK_ADDRESS to 1
Root DEVICE_INFO reports DMX Address 1, footprint of 10.
The shall rule may be technically violated but is of no consequence to a controller, more important is that the footpring has changed which is not prohibited by the standard.

Next we set the BLOCK_ADDRESS to 2.
Root DEVICE_INFO reports DMX Address 2, footprint of 10.
The shall rule has been explicitly violated as the root DMX address has now changed.

The Idea of allowing the flexibility to remain while contiguous, is to enable the many controllers that don't really do sub-devices to change the BLOCK_ADDRESS (providing that the responder is already contguously addressed) by using the setting the root DMX Address, which I see nothing in the standard to counter...

If one is not able to track the other, it makes a nonsense of the whole scheme.