Digital Temperature and Humidity ControllerTemperature and Humidity SensorMODBUS Temperature Humidity TransmitterSensors

Specifications

It's suitable for intelligent building,clean room,workshop,agricultural greenhouses,storage,super market,cold room,freezer,etc.

Electrical characteristics and standards compliant :

 

1) The main communication interface which connected with PC uses the standard COM port of serial RS485 and block terminal;

 

2) Transporting mode of information is an asynchronous mode, the byte format is with 1 start bit, 8 data bits, and 1 stop bit,none checkout.

 

3) Data transmitting velocity is optional,that are 1200b/s, 2400b/s, 4800b/s, 9600b/s, 19200b/s,default data is 9600b/s.

 

4) Comply with the protocol standard of MODBUS RTU;

 

Basic rules of protocol :

 

Following protocols are determined by the communication protocol of loop controller and serial communication loop equipments.

 

1)  All RS485 communication loop should be comply with the mode of master/slave. In this way, the data could be transferred between in a master station (such as: PC) and multiple sub-stations (such as: HS320). It could not be started from sub-stations for each communication.

 

2) All the transmission communications in the communication loop of RS485 are initialized and controlled by the master station.

 

3) All the loop of transferring are divided into two ways:

A) Master/slave transmission;

B) Slave/Master transmission;

 

4) All the transmission communications in the communication loop of RS485 are transferred as the way of information frame.

 

There will be no any response when master station or sub-station received an unknown information frame command

 

“Information Frame” is a character string,and the character string is made up by bytes( most 255 bytes).It is a asynchronous serial data,which is made up by the information header and sending code data.This communication mode is also compatible with RTU communication agreement.