滑动窗口技术在智能仪表离线交易记录上传中的运用

Application of Sliding Window Technology in Uploading Offline Transaction Records of Intelligent Instruments

摘要:

RS485通信协议在工业数据通信领域中被广泛采用,它具有组网简单、抗干扰能力强、传输距离远等诸多优势。但RS485通信协议在传输层的实现没有统一标准,需要各个工业厂商自己定义,而大部分厂家采用的是单数据包的询问应答模式,导致信道利用效率低。当数据传输量小的时候,时间成本的浪费并不突出,然而但随着数字智能设备的不断发展,通信数据量的不断增大,RS485协议在实际的应用中也凸现一些弊端,如传输效率低,信道利用率不高等问题。TCP协议是一种面向连接的、可靠的、基于字节流的传输层通信协议。TCP滑动窗口技术是一种成熟可靠的传输层通信协议,它具有差错控制、流量控制、较高的数据传输效率等优势,将TCP滑动窗口技术应用于RS485通信协议必将极大的改善目前工业领域数据通信的现状。

Abstract:

RS485 communication protocol is widely used in the field of industrial data communication. It has many advantages, such as simple network structure, strong anti-interference ability and long transmission distance. However, there is no unified standard for the implementation of RS485 communication protocol in the transmission layer, which requires the definition of each industry manufacturer, and most manufacturers use the query response mode of single data packet, which leads to the low efficiency of channel utilization. When the data transmission is small, the waste of time cost is not outstanding. However, with the continuous development of the digital intelligent equipment and the increase of the amount of communication data, the RS485 protocol also shows some drawbacks in the practical application, such as low transmission efficiency and low channel utilization. TCP protocol is a connection oriented, reliable, byte stream based transport layer communication protocol. TCP sliding window technology is a mature and reliable transmission layer communication protocol. It has the advantages of error control, flow control, high efficiency of data transmission and so on. The application of TCP sliding window technology to the RS485 communication protocol will greatly improve the current data communication in the industrial.