Chen P.-F.,Shandong Taikai Automation Co. |
Liu Y.-J.,Shandong Taikai Automation Co. |
Song C.-H.,Shandong Taikai Automation Co. |
Chen L.,Shandong Taikai Automation Co. |
Xu W.,Shandong Taikai Automation Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011
In order to improve the communication efficiency of RS485 bus to the maximum extent, through the study of characteristics of RS485 communication, and starting from the protocol calls strategy mechanism of the application software on top of the main device, the timing cyc-call strategy is substituted by adaptive-call strategy. The main device adjusts the call time interval according to the the length of uploaded code from the subordinate device automatically, thereby reducing the bus idle time, improving communication efficiency to a great extent, as well as ensuring the reliability of data communications, and finding a fundamental solution to the RS485 communication bottleneck. This article takes the Protocol 103 for an example to explain how to upgrade the timing cyc-call strategy to adaptive-call strategy in the actual programming, and provides a flow chart of transformation as well as the C source code.