Atal AT-VLC-ND-A2-RS User manual

1
User’s Manual
Carbon Dioxide Detector
Model: AT-VLC-ND-A2-RS
Specifications
General Data
Power supply
24VAC/VDC±10%
Consumption
3.5 W max. ; 2.0 W avg.
Analog outputs
Two 0~10VDC/4~20mA for CO2/Temperature measurements
PID control output is selectable for CO2
RS485 interface
Modbus protocol
4800/9600(default)/19200/38400bps; 15KV antistatic protection,
independent base address.
LED light condition selectable
3-color mode (default)
Green: ≤1000ppm
Orange: 1000~1400ppm
Red: >1400ppm
Red flashing: CO2 sensor faulty
Working light mode
Green on: working
Red flashing: CO2 sensor faulty
Operation condition
0~50℃; 0~95%RH, non condensing
Storage condition
-10~60℃ / 0~80%RH
Net Weight / Dimensions
190g /117mm(L)×95mm(W)×36mm(H)
Installation
wall mounting with 65mm×65mm or 2”×4”wire box
Housing and IP class
PC/ABS fireproof plastic material, protection class: IP30
Standard
EMC approval
Carbon Dioxide
Sensing element
Non-Dispersive Infrared Detector (NDIR)
CO2 measuring range
0~2000ppm (default)
CO2 Accuracy @22℃(72℉)
±60ppm + 3% of reading or ±75ppm (whichever is greater)
Temperature dependence
0.2% FS per℃
Stability
<2% of FS over life of sensor (15 year typical)
Pressure dependence
0.13% of reading per mm Hg
Calibration
ABC Logic Self Calibration Algorithm

2
Dimension and Mounting
◆Please note the power supply is 24VAC/VDC±10%. Don’t install the detector with over the voltage.
◆First of all, please prepare a flat head screwdriver and gently put it deep inside of the hole on the bottom
of the detector housing. Then slant the screwdriver and open the cover gently. Do not mount it near
diffuser or any steam source, in direct sunlight.
◆Mount the wall plate. Place the detector against the wall at desired location; make sure wires can be
passed through the notch on the wall plate.
◆Connect wires to terminal strips. Make sure wiring connection correct and secure.
◆Finally close the cover gently.
Wiring Diagram
Response time
<2 minutes for 90% step change typical
Signal update
Every 2 seconds
Display resolution
1ppm
Warm-up time
2 hours (first time) / 2 minutes (normal operation)
Temperature and RH (option)
Temperature sensor (selectable)
Digital integrated temperature and humidity sensor or
NTC thermistor
Measuring range
-20~60℃/-4~140F 0~100%RH relative humidity
Accuracy
Temp.: <±0.5℃@25℃RH: <±3.0%RH （20%~80%RH）

3
Analog Output Selection
◆The default analog output is 0-10V. If you want to change to 4-20mA output, please follow the below.
◆ Open the cover, you can see five black blocks of J1 & S1~S4. The J1=OFF corresponding
to 0-10V and the J1=ON corresponding to 4-20mA. At the same time, connect ‘V’ side of S1~S4
corresponding to 0-10V and connect ‘A’ side of S1~S4 corresponding to 4-20mA. As shown figure 4.
Modbus Register
Mode: RTU (MSB First)
Baud Rate: 1-4800 2-9600 3-14400 4-19200 5-38400 bps default: 2-9600bps
Start Bits: 1
Data Bits: 8
Stop Bits: 1 / 2 default : 2
Parity: None / Odd / Even default: None
Modbus Address: 1~247 default: 1
Register Map
Support Function: 3 4 6 16
Starting
Register
Decimal
Data Description
Function
Read/
Write
Length
Format
Valid Response
0
CO2 Measurement
4
R
2
Float inverse
0~5000 ppm
2
Temperature Measurement
4
R
2
Float inverse
0.0~50.0 ℃
4
Humidity Measurement
4
R
2
Float inverse
0.1~100.0 %RH
Starting
Register
Decimal
Data Description
Function
Read/
Write
Length
Format
Selection
Default
0
Modbus Address
3/6
R/W
1
INT16
1~247
1
1
Modbus rate
3/6
R/W
1
INT16
1-4800bps
2-9600bps
3-14400bps
2

4
4-19200bps
5-38400bps
2
Modbus Stop Bit
3/6
R/W
1
INT16
1-None 1Stop Bit;
2-None 2Stop Bit;
3-Odd 1Stop Bit;
4-Even 1Stop Bit
2
3
CO2 offset
3/6
R/W
1
INT16
-300~300ppm
0
4
Temperature offset
3/16
R/W
2
Float inverse
-5.0~5.0 ℃
0.0
6
Relative Humidity offset
3/16
R/W
2
Float inverse
-10~10 %RH
0.0
8
Logic of Relay Control
3/16
R/W
1
INT16
0- Increase CO2
1- Decrease CO2
1
10
Warm-up Time
3/6
R/W
1
INT16
1~600 Seconds
10
11
CO2 Max. Measurement
3/6
R/W
1
INT16
400~10,000 ppm
2000
12
CO2 PID Control Setpoint
3/6
R/W
1
INT16
400~5,000 ppm
800
13
CO2 Relay Control min. Setpoint
3/6
R/W
1
INT16
400~5,000ppm
780
14
CO2 Relay Control max.
Setpoint
3/6
R/W
1
INT16
400~5,000ppm
820
15
LED work mode
3/6
R/W
1
INT16
0- 3 color mode;
1- 2 color mode
0
16
Buzzer alarm
3/6
R/W
1
INT16
0- Disable
1- Enable
1
17
Buzzer alarm Setpoint of CO2
3/6
R/W
1
INT16
400~5,000ppm
1400
18
LED switch from green to yellow
3/6
R/W
1
INT16
400~5,000ppm
1000
19
LED switch from yellow to red
3/6
R/W
1
INT16
400~5,000ppm
1400