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2/16/2008 5:47 PM | |
Joined: 9/27/2006 Last visit: 9/22/2024 Posts: 12282 Rating: (2684) |
Hello S7Magr; In Siemens' S7 world, there are no high-availability CPUs for the S7-300 family. For the S7-400 family, there are 2 high-avalabilitymodels offered, S7-414-4H and S7-417-4H, with dedicated F.O. connectors to establish software synchronization between Primary and stand-by units, and to ensuremicrosecond switch-over in case of fail-over.The package requires special backplane ("segregated"), possibly redundant power supplies, 2 H-CPUs with F.O. interface, specialized function blocks for synchronisation (licensed) and redundant Profibus-DP I/O using Y-Links. You will find a lot more information on this system on the Siemens S7-400 portal. If you wish to use S7-300 CPUs in redundant mode, the only option is the Software Redundancy (SWR) package. It is a software that you add to step 7 (licensed); it requires that you select one dedicated network interface, IE, MPI or Profibus-DP to establish synchronisation between the 2 CPUs; fail-over time will be counted in seconds, especially if you use the MPI connection (187,5 kBaud) for redundancy. So performance with SWR is not at all on the same level as that of the H-CPUs in the S7-400 family. Please look at the SWR manual to have a better idea of what is involvedin the implementation ofSWR, what you need to make it work and what you can and cannotdo with it. Hope this helps, Daniel Chartier |
This contribution was helpful to3 thankful Users |
4/25/2012 1:30 PM | |
Posts: 1 Rating: (0) |
thanks ..... |
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