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Modbus TCP with two PLCs in redundancy

AG_AutomacaoAG_Automacao
in PLCnext Engineer

Hello,

I am using two AXC F 3152 in redundancy.

I will access the PLC through Modbus TCP using the primary PLC's IP.

When a function change occurs due to redundancy, that is, the primary PLC changes to Backup and the Backup PLC changes to primary, as is the access IP, the Backup PLC assumes the IP of the primary PLC to maintain communication with the Modbus ?

Is there any specific configuration for this?

Grateful for the attention.

Comments

  • FriedrichFriedrich

    Hello,

    At the ASR system there are two PLCs forming a redundant system. One PLC is named FIRST and the other is named SECOND. One of those PLCs has the redundancy role Primary and the other has the redundancy Backup. In case of a redundancy switchover the redundancy role will be switched.

    The IP address assignment of the PLCs does not refer to the redundancy role but refers to FIRST or SECOND respectively.

    If you communicate via Modbus TCP Client and there is a redundancy switchover of the PLCs, you will have to change the Server IP-address of your Modbus TCP Client configuration.

    At our visualisation system, for example, you can enter at the Modbus TCP Client configuration the Server IP-address and additionally a Backup IP-address:

    image.png

     

  • AG_AutomacaoAG_Automacao
    https://forum.plcnext-community.net/discussion/comment/12671#Comment_12671

    Thanks for your attention Friedrich,

    His information was of great value.

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