In guarantee the absolutely agree i

In guarantee the absolutely agree in the baud rate, information frame data bits number, start bit number, number of stop bits, odd/even check or without the check digit between the two communication site, the communication can be created in the process of debugging. The data exchange between PLC and 20 AI-708 smart meters is very stable, accurate and reliable. By adopting AIBUS agreement, the communication between S7-200 programmable controller and many intelligent instruments is implemented efficiently in the form of hexadecimal number, and the parameter setting is convenient, the control and operation of the industrial field device is easy. The temperature control system introduced in this paper can meet the different process requirements, and it’s control method is convenient, practical and feasible. RS485 network can communicate serial polling with much more intelligent instruments. But the longer communication distance, the lower communication baud rate. The use of optical fiber and expensive consumables can be prevented by realizing the communication function only, and then the cost is reduced.