There are two ways to establish redundant S7 connection between redundant system and PC: one is to use "S7-REDCONNECT" software package, and its configuration process is complicated, and the steps are as follows: configure S7-400h；; ; Configure PC station; Configure fault-tolerant connections; Set the PG/PC interface of WINCC station; Configure WINCC station. Please refer to Getting Started with RedConnect for the specific configuration process. The second way is to use the channel redundancy function of WINCC on the PC side, through the dynamic wizard "Set Redundant Connection", and create a SIMATICS7ProtocolSuite to complete the dynamic connection switching. The steps are as follows: firstly, according to the connection mode with a single CPU, define the main connection attribute under WINCC project/variable management /S7 protocol set/Ethernet/connection attribute; Then run the dynamic wizard/system function/set up redundant connections and define redundant connections in the screen editor: follow the wizard steps, first select the main connection, and then define the parameters of the backup connection, such as "H 1, 0800069D78 1C, 1, 3,02", where h/kloc-. 0800069D78 1C is the MAC address of Ethernet 443- 1 card of redundant CPU, where 0 stands for Racknumber, 3 stands for slot number, and 02 stands for connectionresource. Select "automatic switching". After definition, WINCC will automatically generate scripts. Reference question ID:7560, question ID:24 18 1.