Features of the gas sensor module

★The whole machine is small in size and light in weight

★ Professional selection of imported sensors, which can be equipped with electrochemical, catalytic combustion, infrared principle, thermal conductivity principle,PID and other sensors.

★ High precision, high resolution, and rapid response.

★ Data recovery function eliminates the worries caused by accidental operations.

★ Factory precise calibration, no need for further calibration. .

The analog voltage or current and serial port are output simultaneously, which is convenient for customers to debug and use.

★ The most precise circuit design and manufacturing process, complex production but simple to use.

★ It can be connected to a computer for communication and self-calibration.

It comes with a built-in zero-point fine-tuning function, making it convenient to select reference data.

★ Low-power products with portable power supply can be widely used in analyzer instruments, atmospheric and environmental unmanned aerial vehicle monitoring.

 

Gas sensor module
Working voltage	12-24V	Baud rate	9600,N,8,1
Measure gas	Optional	Detection principle	Optional
Sampling accuracy	±%3F.S	Response time (T90	<30S
Repeatability	±1%F.S	Working humidity	0-95%RH，(No condensation
Working temperature	-20 ～ 50℃	Long-term drift	≤±1%（F.S/years）
Storage temperature	-20 ～ 50℃	Preheating time	10S
Working current	≤50mA	Working air pressure	101Kpa±20KPa
Installation method	M20*1.5 External thread	Warranty period	1 year
Output interface	RS485+4～20mA	Shell material	ABS/Aluminum alloy
Service life	2～3 years	External dimensions (excluding pins)	Diameter 48   high95mm
Measurement range	For details, please refer to the selection table.

Gas sensor module size diagram and pin definitions：

 

 

Schematic diagram of the 4-20mA connection for the gas sensor module:

 

Schematic diagram of RS485 connection for gas sensor module:

 

Application sites of gas sensor modules：

Pharmaceutical research, school research, pharmaceutical production workshops, tobacco companies, environmental monitoring, building construction, fire alarm, sewage treatment, petroleum and petrochemical, chemical plants, smelters, steel mills, coal mines, thermal power plants, boiler rooms Gas filling stations, garbage treatment plants, tunnel construction, oil pipelines, aerospace, industrial gas process control, indoor air quality testing, underground gas pipeline maintenance, safety protection in hazardous areas, military equipment testing, etc.

 

ModbusRTU   Instruction set

This agreement lists the main registers of toxic gas detectors, toxic gas detector modules, dust detectors, temperature and humidity detectors, etc. Some specific registers are only valid in their respective devices. For example, the real-time values of temperature and humidity are only valid in temperature and humidity detectors.

 

 

• The RS485 interface adopts the standard modbusRTU protocol, with a baud rate of 9600, no parity bit, 8 data bits, and 1 stop bit.
• Supported function code: 03: Read single or multiple register values; 06: Write a single register value.

 

• The content of the register is read using the 03 function code

03The format for using function codes

Sent by the host：

Address

03

High starting address

Low starting address

Number of registers high bits

The number of registers is low.

CRCL

CRCH

Note: Data address range: 0 to 47 (i.e., 0x0000 to 0x002F). The valid data addresses for users are as follows. The remaining addresses will be reserved.

 

Slave machine reply：

Address

03

Byte count n*2

Data 1 High position

Data  1 Low position

…

Date  n  hight position

Date n low position

CRCL

CRCH

Note: When the host reads data, the maximum address must not exceed 0x002F, that is, the sum of the starting address and the number of data points must not exceed 0x002F; otherwise, an error will be reported and the reading will fail.

 

Note: The six parameters of real-time detection value, low alarm value, high alarm value, full scale of the equipment, alarm hysteresis, and concentration at the calibration point need to be calculated in combination with the number of decimal places. For example, if the real-time detection value is 1256 in decimal and the decimal place of this equipment is 2, then the actual real-time detection value is 12.56. The same applies to the other five parameters.

1. Read the real-time detection value (FE is the broadcast address, which must be changed to a specific slave number when in use, the same below)

Sent by the host：01 03 00 00 00 01 84 0A

Slave machine reply：01 03 02 00 02 39 85 （The real-time concentration of the gas is 2ppm）

 

1. Read the low alarm value

 Sent by the host：01 03 00 01 00 01 D5 CA

Slave machine reply：01 03 02 00 40 B9 B4 （The underreported value is 64）

 

1. Read the high reported value

 Sent by the host：01 03 00 02 00 01 25 CA

Slave machine reply：01 03 02 00 64 B9 AF  （The high reported value is 100）

 

1. Read the device address (use the universal code FE when the device address is unknown. The universal code is applicable to all instructions of 03 and 06)

Sent by the host：01 03 00 0C 00 01 44 09 

Slave machine reply：01 03 02 00 01 79 84 （address #1）

 

1. Read the full scale of the device

Sent by the host：01 03 00 0B 00 01 F5 C8

Slave machine reply：01 03 02 03 E8 B8 FA （The full scale is 1000）

 

1. Read the type of device

 Sent by the host：01 03 00 0E 00 01 E5 C9

Slave machine reply：01 03 02 00 09 78 42  （Equipment inspection objectCO）

(The following is represented in Hex codes, including but not limited to the types of gases listed in the table)

List of names and numbers of some gases：

0x00	空	0x01	ASH3	0x02	Br2	0x03	C2H4
0x04	C7H8	0x05	CH4	0x06	CH2O	0x07	CL2
0x08	CLO2	0x09	CO	0x0A	CO2	0x0B	COCL
0x0C	ETO	0x0D	Ex	0x0E	F2	0x0F	GEH4
0x10	H2	0x11	H2S	0x12	HBr	0x13	HCHO
0x14	HCL	0x15	HCn	0x16	HF	0x17	N2
0x18	NH3	0x19	NO	0x1A	NO2	0x1B	NOX
0x1C	O2	0x1D	O3	0x1E	PH3	0x1F	PLG
0x20	PM2.5	0x21	PM10	0x22	S1H4	0x23	SO2
0x24	TBM	0x25	THT	0x26	VOC	0x27	XXXX
0x28	PM	0x29	H2O2	0x2A	CH3Br	0x2B	SF6
0x2C	SO2F2	0x2D	Ar	0x2E	He	0x2F	NMP
0x30	C2H3N	0x31	PM100	0x32	PM1.0	0x33	CH
0x34	C3H3N	0x35	C3H6O	0x36	C3H8	0x37	C6H6
0x38	C8H10	0x39	C2H2	0x3A	C2H6	0x3B	C4H10

1. Read the decimal point

 Sent by the host：01 03 00 0D 00 01 15 C9

Slave machine reply：01 03 02 00 02 39 85  （2位小数点）

 

1. Unit reading

 Sent by the host：01 03 00 17 00 01 34 0E

Slave machine reply：01 03 02 00 F6 38 02 （ppm）

 

0000：empty； 00F6：ppm； 005F：ppb； 200E：%LEL； 380E：%VOL； 3900：ug/m3； 4000：mg/m3

 

1. Read and retrieve the difference

 Sent by the host：01 03 00 24 00 01 C4 01

 Slave machine reply：01 03 02 00 14 B8 4B（The hysteresis value is：0x0014=20）

 

To modify the register content, use the 06 function code (when the specific address number is unknown, the universal code FE can be used).

Sent by the host

Address

06

High bit of the address register

Low bit of the address register

Modify the high value

Modify the lower digit of the value

CRCL

CRCH

Slave machine reply

Address

06

High bit of the address register

Low bit of the address register

Modify the high value

Modify the lower digit of the value

CRCL

CRCH

 

1. Modify the low report register

 

Sent by the host：01 06 00 01 00 30 D8 1E

Slave machine reply：01 06 00 01 00 30 D8 1E（The low reporting for repair has been changed0x30，That is 48）

 

1. Modify the high report register

Sent by the host：01 06 00 02 00 64 29 E1

Slave machine reply：01 06 00 02 00 64 29 E1（The high report has been revised  0x64，That is  100）

 

1. Modify the address register

Sent by the host：01 06 00 0C 00 02 C8 08

Slave machine reply：01 06 00 0C 00 02 C8 08（The address has been modified to2）

Note: After executing the instruction to modify the address register, when the next instruction is executed, the address byte must be replaced with a new address; otherwise, normal communication cannot occur and the CRC16 check code will need to be recalculated.

 

1.  Zero adjustment of the equipment

Sent by the host：01 06 00 19 00 00 58 0D

Slave machine reply：01 06 00 19 00 00 58 0D(Zero adjustment in a clean and atmospheric environment

 

1. Equipment calibration

Sent by the host：01 06 00 19 08 29 9E 13（Calibrated as  2089，It has nothing to do with decimal points）

Slave machine reply：01 06 00 19 08 29 9E 13

 

1.  Modify the hysteresis

Sent by the host：01 06 00 24 00 32 48 14

Slave machine reply：01 06 00 24 00 32 48 14（Modify the lag to 0x0032,That is   50）

 

 

Register function	Register address	range	Read/Write
Real-time concentration	0x0000	----	Read-only
Low alarm value	0x0001	It is generally for the range  20%	Readable/writable
High alarm value	0x0002	It is generally for the range  50%	Readable/writable
PM1.0	0x0005	0-65535, 16-bit unsigned integer	Read-only, dust effective
PM2.5	0x0006	0-65535, 16-bit unsigned integer	Read-only, dust effective
PM10	0x0007	0-65535, 16-bit unsigned integer	Read-only, dust effective
Temperature	0x0008	A 16-bit signed integer. The actual temperature should be divided by 100	Read-only, temperature and humidity are valid
Humidity	0x0009	A 16-bit unsigned integer. The actual humidity should be divided by 10	Read-only, temperature and humidity are valid
Equipment full scale	0x000B	----	Read-only
Equipment address	0x000C	The factory version is No. 1	Readable/writable
Number of decimal places	0x000D	0,1,2,3	Readable/writable
Types of equipment	0x000E		Read-only
"Unit	0x0017	0000：empty； 00F6：ppm； 005F：ppb；  200E：%LEL；  380E：%VOL；  3900：ug/m3；  4000：mg/m3	Read-only
Zero adjustment/calibration	0x0019	Only effective for gases	Just write
Alarm hysteresis	0x0024	As of the factory  0	Readable/writable
Calibration concentration	0x0026	Actual standard gas concentration	Readable/writable