S7-300 PLC Redundancy with large volume of data

[jadeinwa]

Hi,

I am setting up a redundant system with 2 S7-317 PLCs and some redundant ET-200 M slaves. The backlink is MPI.

There is 15Kbyte backup data to be transfered between 2 PLCs. However, in Siemens manual, it is said that the max volume of data can be transfered via MPI in redundant system is 1Kbyte.

Does anybody know how to deal with this situation?

Many Thanks

Jadeinwa

 

[dchartier]

Hello jadeinwa;
Looking at the Software redundancy limits of data transfer over MPI, it seems that you would have to connect the CPUs through a larger-bandwith network to process your 15 kB of data. I would go directrly to Industrial Ethernet(CP343-1) with an ISO connection, working at 10 MB, or a Profibus FDL connection at 12 MB (CP342-5 or directly on the CPU-DP connector). In both cases, the transfer time of redundant data is estimated at 4 sec.
Hope this helps,
Daniel Chartier

 

[jadeinwa]

dchartier,

Thanks for you reply.


I checked Siemnes manual 'Software Redundancy for S7-300 and S7-400'. It is said in 4.1 that 'Max. volume of redundant-backup data transferable is 8Kbyte for S7-300'.

Is it possible for S7-300 to transfer 8K or more data betwen 2 CPUS over Ethernet in the redundant system?

jadeinwa