Delta Controls
Document Edition 4.2
Page 11 of 43
CO2 (AI4)
On BACstats with the on board carbon dioxide (CO2) sensor option (C), the CO2 sensor shows up as
analog input 4. When configured as a LINKnet device with display code 1111 input scaling is done in
the parent controller (see Appendix B LINKnet). Download the CO2 scale range AIC from the DNS-
24 product page on the support site. CO2 is only available on the DNS-C24, DNS-CH24, and DNS-
CHM24.
Special Handling
- The CO2 sensor factory calibration can be effected by rough
handling of the device so extra care should be taken when installing.
Warmup Time
- On initial powerup the CO2 readings are held at 380ppm until the
sensor is "warmed up" (approximately 3 minutes). This prevents artificially high CO2
readings initiating a demand control ventilation sequence.
Minimum CO2 Reading
- The CO2 input is has a low limit of 380ppm, it will not
display values lower than this. This is slightly below the accepted outdoor ambient CO2
levels which is relatively constant across the world. Readings below this outside of an
environment chamber are essentially impossible. This will ensure that the sensor does
not report unbelievable values to building operators during unoccupied periods.
Motion (BI5)
On BACstats with the on board motion sensor option (M), the motion sensor shows up as binary input
5. The motion option is only available on the DNS-M24 and DNS-CHM24.
The Motion sensor has a configurable latch time set in seconds using AV38. Note the configurable
latch time only applies when the BACstat is configured for MS/TP and has a default value of 60
seconds. This ensures that motion transitions are not missed when reading the motion sensor status
from a remote panel using default data exchange settings which would typically read the value every
30 seconds. In LINKnet mode AV38 is not used, the latch time is fixed at 2 seconds. Any extended
latch time should be programmed using GCL in the parent controller.
System Events and Statistics
System Stats (AV34)
The Description field in this object provides a count of notable events that have occurred. Each
statistic consists of an event code (H- Hardware, C- Communication, S-S two-digit code) and
an event count. With the exception of the reset count (H04) and the flash programming count (H05),
event counts are reset on power up. The PresentValue indicates how many different types of events
have occurred since power up.
Code
Description
H04
Reset count
H05
Flash programming count
H06
Flash operation failure
H08
I2C communication failure
C01
Communication overflow
C02
Buffer unavailable
C03
Into Sole Master
C04
DNA conflict
C05
MAC address conflict
C06
Receive overrun
C07
CRC error
C08
MSTP pass token timeout
