PlanoSpot 360 DALI-2 S DE manual
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8.2
Determining a value via the DALI bus
According to DALI standard IEC 62386-103/304, the value of a light sensor instance is obtained
either by querying directly or by evaluating the events.
8.2.1
Direct queries
The following steps must be carried out in order to query the value directly:
1.
Address the DALI telegram "QUERY INPUT VALUE" to the desired device and with the
desired instance number of a light sensor.
2.
Multiply the returned value by 64 and save in a variable of at least 16 bits.
3.
Address the DALI telegram "QUERY INPUT VALUE LATCH" to the previous device with the
previous instance number.
4.
Divide the returned value by 4 and add to the previous variables.
Example as pseudo code:
inputValue = QUERY_INPUT_VALUE()
Variable = inputValue × 64
inputValue = QUERY_INPUT_VALUE_LATCH ()
Variable = Va inputValue ÷ 4
8.2.2
Evaluating events
A light sensor instance event can be triggered cyclically or in the case of certain changes to the
value. The following steps are necessary in order to present the value that has been received in
lux:
1.
Extract the 10-bit event information from the 24-bit light sensor event telegram that has
been received and save it in a variable of at least 16 bits.
2.
The variable must then be multiplied by 16 in order to present the value in lux.
Example as pseudo code:
inputValue = EVENT_INFO
Variable = inputValue × 16
As the event information is limited to 10 bits, only increments of 16 lux are possible. If a
more precise value is required, this can be queried directly in full resolution. See
