S7-300/400 PLC系统软件冗余调试常见问题

(S7-300400 PLC system software redundancy debugging common problems.doc) The common problems in debugging the software redundancy of the S7-300/400 PLC system are as follows: 1. Hardware Configuration: When setting up the software redundancy system, it is important to pay attention to the hardware configuration. The redundancy control of the software redundancy system can only be achieved through ET 200M. The configuration of the A and B stations must be consistent, and the configuration can be copied from the ET200M and used in the configuration of the other station. 2. Supported Modules: It is important to determine which modules can support software redundancy. This information can be found in the software redundancy manual or in the FAQ section of the provided link. 3. FC100 "SWR_START" Data Area: In the FC100 "SWR_START" data area, it is crucial to distinguish between redundant and non-redundant data areas. The redundant data area includes the process image output area/DB/IEC/M, while the non-redundant data area includes DB. The main difference is that the data in the redundant data area is synchronized between the primary and backup stations, while the data in the non-redundant DB area is transmitted according to the defined A-B B-A direction. It is important to ensure that the lengths of the A and B stations are consistent, and if not required, the length should be defined as 0. 4. Impact of DB Blocks: In a software redundancy system, there is an impact of DB blocks. Special function DB blocks are used in the soft redundancy system. These blocks have a specific effect on the operation of the system. Overall, the debugging of the software redundancy of the S7-300/400 PLC system requires careful attention to hardware configuration, supported modules, data areas, and the impact of DB blocks. By addressing these common problems, the software redundancy system can be effectively and efficiently debugged and maintained.