44
Industrial Wall Control Application Notes
Start pulse
Pause
L HDL HDL
msb DATA lsb
0 0 1 0 1 1 0 0
0 0 0
0
0 0 0 0
msb Zero byte lsb
Pause
Temperature and Humidity bit stream
The IWC05 outputs Humidity and Temperature readings for use with a PLC or building management system.
Humidity is output on terminal OUT6 of J7 and Temperature is output on terminal OUT7 of J7. The Temperature
data word is 9 bits after 7 bits of leading zero's, while the Humidity data byte is 8 bits after a leading zero byte of 8
bits. The temperature value in binary is 10 x the Temperature reading (for example: 20.6
°
C is sent as a value of
206).
The below example (shown at 1sec/div) is 44%RH which is 00101100 in binary.
The bit format is S L H D L H D L …H D L P where:
S = Start pulse
L = Low
H = High (for synchronisation purposes)
D = Data state (high or low)
P = Pause
The Humidity Bit stream is as follows: The Temperature Bit stream is as follows:
Start Pulse Start Pulse
Bit 15 to Bit 8 all Zero (0) Bit 15 to Bit 9 all Zero (0)
Bit 7 (msb of data) Bit 8 (msb of data)
.. ..
.. ..
Bit 0 (lsb of data) Bit 0 (lsb of data)
Pause
Pause
The bit timing is as follows:
Start pulse
750mSec on, 250mSec off
A High Bit
500mSec on, 250mSec off
A Low Bit
250mSec on, 500mSec off
Pause
1000mSec off
Update Rate
14 seconds
Shift in PLC
LEFT