SM7320B
RS485 rack temperature and humidity sensor
User Manual
File Version: V22.4.18
SM7320B RS485 Rack Temperature and Humidity Sensor
http://www.sonbus.com/
SM7320B using the standard RS485 bus MODBUS-RTU protocol,easy access to PLC，DCS and other instruments or systems for monitoring temperature,humidity state quantities.The internal use of high-precision sensing core and related devices to ensure high reliability and excellent long-term stability,can be customized RS232,RS485,CAN,4-20mA,DC0~5V\10V,ZIGBEE,Lora,WIFI,GPRS and other output methods.
Technical Parameters
| Technical parameter | Parameter value |
| Brand | SONBEST |
| Temperature measuring range | -30℃~80℃ |
| Temperature measuring accuracy | ±0.5℃ @25℃ |
| Humidity measuring range | 0~100%RH |
| Humidity accuracy | ±3%RH @25℃ |
| Communication Interface | RS485 |
| Default baud rate | 9600 8 n 1 |
| Power | DC9~24V 1A |
| Actual power consumption | <20mA @9V |
| Running temperature | -40~80°C |
| Working humidity | 5%RH~90%RH |
Product Size 
How to wiring?
※ Note: When wiring,first connect the positive and negative poles of the power supply, and then connect the signal line
Application solution
- RS485 Wiring
- Current tow – wire wiring
- Current three – wire wiring
- Voltage wiring
- Voltage T&H wiring
How to use?
Food storage
Temperature and humidity are very important for food storage. Changes in temperature and humidity will bring about food spoilage and cause food safety problems. Monitoring of tem-perature and humidity is benefi-cial to the timely control of rele-vant personnel.
Greenhouse
Cooperate with sensors to effectively manage, create a good lighting environment for crops, and promote better photosynthesis 
Tobacco industry
Tobacco raw materials need to be con-trolled in temperature and humidity during fermentation.Temperature and humidity sensors can be used to monitor the temperature and humidity when the site environment is convenient.In a com-plex environment,the temperature and humidity sensors such as RS485 can be used to detect and control tobacco The temperature and humidity of the package can avoid insect pests.If not handled properly,it will cause a large amount of loss of raw materials.
Communication Protocol
The product uses RS485 MODBUS-RTU standard protocol format, all operation or reply commands are hexadecimal data. The default device address is 1 when the device leaves the factory, and the default baud rate is 9600,8,n,1.
- Read data (function code 0x03)
Inquiry frame (hexadecimal), sending example: query 1 data of 1# device, the upper computer sends the command: 01 03 00 00 00 01 84 0A .Address Function Code Start Address Data Length Check Code 01 03 00 00 00 01 84 0A For the correct query frame, the device will respond with data: 01 03 02 00 79 79 A6 , response format:
Address Function Code Length Data 1 Check Code 01 03 02 00 79 79 A6 Data description: The data in the command is hexadecimal, take data 1 as an example, 00 79 is converted to decimal value as 121, assuming the data magnification is 100, then the real value is 121/100=1.21, Others and so on.
- Common data address table
Configuration Address Register Address Register Description Data Type Value Range 40001 00 00 temperature Read Only 0~65535 40101 00 64 Model Code Read/Write 0~65535 40102 00 65 total number of measuring points read/write 1~20 40103 00 66 device address read/write 1~249 40104 00 67 baud rate read/write 0~6 40105 00 68 communication mode read/write 1~4 40106 00 69 protocol type read/write 1~10 - Read and modify device address
(1) Read or query device address
If you don’t know the current device address and there is only one device on the bus, you can query the device address through the commandFA 03 00 66 00 01 71 9E .Device Address Function Code Start Address Data Length Check Code FA 03 00 66 00 01 71 9E FA means 250 is the general address, when you don’t know the address, you can use 250 to get the real device address, 00 66 is the device address register.
For the correct query command, the device will respond, for example, the response data is: 01 03 02 00 01 79 84, and its format parsing is shown in the following table:Device Address Function Code Start Address Model Code Check Code 01 03 02 00 01 79 84 In the response data, the first byte 01 represents the real address of the current device.
(2) Change device address
For example, if the current device address is 1 and we want to change it to 02, the command is: 01 06 00 66 00 02 E8 14.Device Address Function Code Register Address Target Address Check Code 01 06 00 66 00 02 E8 14 After the change is successful, the device will return the information: 02 06 00 66 00 02 E8 27 , and its format analysis is shown in the following table:
Device Address Function Code Register Address Target Address Check Code 02 06 00 66 00 02 E8 27 In the response data, after the modification is successful, the first byte is the new device address.
Generally, after the device address is changed, it will take effect immediately. At this time, the user needs to change the query command of his software accordingly. . - Read and modify baud rate
(1) Read baud rate
The default factory baud rate of the device is 9600. If you need to change it, you can change it according to the following table and the corresponding communication protocol. For example, to read the baud rate ID of the current device, the command is: 01 03 00 67 00 01 35 D5 , the format is parsed as follows.Device Address Function Code Start Address Data Length Check Code 01 03 00 67 00 01 35 D5 Read the baud rate code of the current device. Baud rate code: 1 is 2400; 2 is 4800; 3 is 9600; 4 is 19200; 5 is 38400; 6 is 115200.
For the correct query command, the device will respond, for example, the response data is: 01 03 02 00 03 F8 45, and its format analysis is shown in the following table:Device Address Function Code Data Length Baud Rate Code Check Code 01 03 2 00 03 F8 45 According to the baud rate code, 03 is 9600, that is, the baud rate of the current device is 9600.
(2) Change the baud rate
For example, change the baud rate from 9600 to 38400, that is, change the code from 3 to 5, the command is: 01 06 00 67 00 05 F8 16.Device Address Function Code Register Address Target Baud Rate Check Code 01 06 00 67 00 05 F8 16 Change the baud rate from 9600 to 38400, that is, change the code from 3 to 5. The new baud rate will take effect immediately, and the device will lose response at this time, and the baud rate of the device needs to be checked accordingly Modified.
- Read and modify correction value
(1) Read correction value
When there is an error between the data and the reference standard, we can reduce the display error by adjusting the correction value. The correction difference can be modified in a range of plus or minus 1000, that is, the value range is 0-1000 or 64535 -65535. For example, when the displayed value is too small by 100, we can correct it by adding 100. The command is: 01 03 00 6B 00 01 F5 D6 . In the command, 100 is hexadecimal 0x64 ;If you need to reduce it, you can set a negative value, such as -100, the corresponding hexadecimal value is FF 9C, the calculation method is 100 -65535=65435, and then converted to hexadecimal, it is 0x FF 9C. Device The correction value starts from 00 6B. We take the first parameter as an example to illustrate. When there are multiple parameters, the correction value is read and modified in the same way.Device Address Function Code Start Address Data Length Check Code 01 03 00 6B 00 01 F5 D6 For the correct query command, the device will respond, for example, the response data is: 01 03 02 00 64 B9 AF, and its format parsing is shown in the following table:
Device Address Function Code Data Length Correction Value Check Code 01 03 02 00 64 B9 AF In the response data, the first byte 01 represents the real addr ess of the current device, and 00 6B is the first state correction value register. If the device has multiple parameters, other parameters operate in the same way as this The same, generally temperature and humidity have this parameter, and lighting generally does not have this parameter.
(2) Change the correction value
For example, if the current state is too small, we want to add 1 to its real value, and add 100 to the current value. The correction operation command is: 01 06 00 6B 00 64 F9 FD .Device Address Function Code Register Address Target Address Check Code 1 6 00 6B 00 64 F9 FD After the operation is successful, the device will return the information: 01 06 00 6B 00 64 F9 FD , after the successful change, the parameters will take effect immediately.
Disclaimer
This document provides all information about the product, does not grant any license to intellectual property, does not express or imply, and prohibits any other means of granting any intellectual property rights, such as the statement of sales terms and conditions of this product, other issues. No liability is assumed. Furthermore, our company makes no warranties, express or implied, regarding the sale and use of this product, including the suitability for the specific use of the product, the marketabi lity or the infringement liability for any patent, copyright or other intellectual property rights, etc. Product specifications and product descriptions may be modified at any time without notice.
Contact Us
Company: Shanghai Sonbest Industrial Co., Ltd
Address:Building 8,No.215 North east road,Baoshan District,Shanghai,China
Web: http://www.sonbest.com
Web: http://www.sonbus.com
SKYPE: soobuu
Email: sale@sonbest.com
Tel: 86-021-51083595 / 66862055 / 66862075 / 66861077
Sha nghai Sonbest Industrial Co., Ltd
Documents / Resources
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