DIN Rail 2 Channel DALI Interface
Crestron
DIN-DALI-2
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DIN Rail 2 Channel DALI Interface: DIN-DALI-2
Programming Guide – DOC. 7365A
Glossary
Binary Search
This is the method by which ballasts are found using the long address. Since
the long address is 24 bits, it would take too long to query every address.
Instead a binary search queries any ballasts below an address. All ballast
with an address less than the value specified responds. The DIN-DALI-2
hears the response and repeats the process with a lower value (half the
original). If the DIN-DALI-2 does not hear a response then it retries with a
higher value (in between the last two values). This process repeats until a
single ballast is found—that is, when a response is heard after querying long
address 0xLLLLLL but not after querying 0xLLLLLL-1. The ballast with
long address 0xLLLLLL is then assigned the next available short address
and is instructed to not respond to any further binary search queries. The
process starts again until another ballast is found and addressed. The
process repeats until no further ballasts can be found.
Long Address (also known as Random Address)
This is a 24-bit random number generated during the addressing phase that
allows commands to be sent to ballasts that do not have short addresses.
The value of 0xFFFFFF is reserved for unassigned ballasts. A ballast
typically leaves the factory with a long address of 0xFFFFFF.
Short Address
This is the address used under normal operation. It is a value between 0-63.
A value of 255 (0xFF) is reserved for unassigned ballasts. A ballast
typically leaves the factory with a short address of 255.
