I have configure AC500 PLC PM583 for redundant system using CI590-CS31 HA.
It's work good, but its posible if i want to connect the rendundant system to some device using modbus protocol communication ?
Kindly help solving the issue.
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redundancy is possible, but......
Check architecture (it is only experimantal solution - don´t use it at all - not tested yet). There you can see redundant links to "external system".
Actually I have next info:
- there is possible to arrange redundant links via 2 variants (for both is necessary to have redundant communication modules CM577)
First variant - both links/modules are active (send data) - there is possible this CM577 configuration, there is necessary to program logic on second side for checking actual status of each communication link include switch over in case of communication issue. Take into account that there will be discrepancy in signal status/delay (first AC500 CPU "replicate" data to second one in full redundant operation). There is possible to set time period for this "replication" (which is possible to set from 10ms to xxxxms). You can use this solution for visualization without any issue (short delay is not any issue), problem can be for using exchanged data for exact troubleshooting.... (this solution is presented on attached picture).
Second variant which is native to AC500 solution - there is only one communication link active at the same time, in case of switch over second module is active and there is necessary to configure interface according next points:
- there must be set multimaster milticast on both modules
- both modules have the same address, than there is necesary to set short delay in case of switch over
- there will be designed one serial link: external primary device communication port - AC500 primary communiaction port - AC500 secondary communication port - external device secondary communication port. Base on this you will be able to receive data on both external device ports (primary and secondary). Take into account that external device/system has to support multimaster broadcast....
Sorry, that´s all I have now. This was my investigation how is possible to arrange redundant communication link to external system (possibilities and possible issues). There is no real feedback behind this proposal (you will need to do own investigation/testing).....