Zhengzhou Winsen Electronics Technology Co., Ltd

www.winsen-sensor.com

Tel: 86-371-67169097/67169670 Fax: 86-371-60932988

Email: sales@winsensor.com

Leading gas sensing solutions supplier in China!

Communication Protocol

1. General Settings

Table 3

Baud Rate

9600

Data Byte

8

Stop Byte

1

Check Byte

Null

2. Communication Commands

There are two kinds of communication, initiative upload mode and question & answer mode.

Under initiative upload mode, modules upload gas concentration value every other 0.5S.

Note: The module will automatically switch to Q&A mode(question & answer mode) after an

inquiry command is received; The module will automatically switch to initiative upload mode

if no inquiry command is received within 15 seconds under Q&A mode.

Table 4 Data format under initiative upload mode

Gas name: 0x01 is for CH4, while Unit ppm: 0x03 is for ppm.

Concentration(High Byte): The highest bit(bit 8) is for sensor fault judgment; bit 7 is for

sensor concentration judgment.

Note: sensor fault judgment: 1 is for sensor failure, 0 is for no failure.

Sensor concentration judgment: 1 is for concentration over alarm-point, 0 is for under

alarm-point.

Gas concentration value = The low 6 bit of High Byte*256+Low Byte.

Full range= full range (high byte)*256+ full range(low byte) (0x1388=5000ppm, which means

the max UART output is 5000ppm)

To read gas concentration, command line format as follow:

Stable5.

Byte0

Byte1

Byte2

Byte3

Byte4

Byte5

Byte6

Byte7

Byte8

Start

Byte

Gas

Name

Unit

ppm

No. of

decimal

Concentration

(High Byte)

Concentration

(Low Byte)

Full Range

(High Byte)

Full Range

(Low Byte)

Check

sum

0xFF

0x01

0x03

0x00

0x00

0x00

0x13

0x88

0x61

Byte0

Byte1

Byte2

Byte3

Byte4

Byte5

Byte6

Byte7

Byte8

Start

Byte

Reserved

command

Reserved

Reserved

Reserved

Reserved

Reserved

Check

sum

0xFF

0x01

0x86

0x00

0x00

0x00

0x00

0x00

0x79