Modbus Slave mode

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  • #3507
    Avatarcatcute
    Participant

    Hi Mikhail

    I config Communicator as Modbus Slave, and I write a small software to connect with this modbus slave (on the same computer), but the software inform the error that “connection was refuse by server”. And the slave was in the idle state! In Device Data section, it display no data, but I’ve already config tags for this device.
    https://drive.google.com/open?id=1S6wUeXTW07Vhue1PrDqXuze6uKrqXfs5
    https://drive.google.com/open?id=1xE49jA_Wei5TzNs1UGpEhsp9uh1cVyEh
    https://drive.google.com/open?id=11zmRQnibnaP5AxLZPC0PDTFx1GYcIqC2

    #3508
    AvatarPieter
    Participant

    Are you running a modbus simulator on the same computer?
    Have you tried stopping line 1.
    Line 1 and Line 8 are both using same database and settings.
    Might be conflicting.
    I do not know much, only just stared using Rapid scada with my modbus devices this week.

    #3509
    Avatarcatcute
    Participant

    Hi Pieter, Line 1 is configed work as Modbus Master: it will send request and read answer from device. Line 8 is configed as Modbus Slave: it will passsive receive request from another device or software and answer the request. That is my understand, I don’t know it is correct in Rapid Scada or not.

    #3516
    MikhailMikhail
    Moderator

    Hi catcute,
    Could you explain the idea what you are going to implement?
    Even if you switch operating mode to Slave, the existing Modbus driver works as master. Slave means that Communicator waits for incoming connection, TCP slave (TCP server) not Modbus slave.

    #3520
    Avatarcatcute
    Participant

    Hi Mikhail

    I intend to read data of device from my software and maping data to Modbus communicator. If Rapid Scada suport Modbus Slave, I can write data directly use modbus protocol. But with Rapid Scada as TCP server, I still can’t open tcp connection with Local tcp port 502, error:The network connection was refused by the server.

    #3532
    MikhailMikhail
    Moderator

    Rapid SCADA works as Modbus master, and it can be TCP server or TCP slave.

    I still can’t open tcp connection with Local tcp port 502, error:The network connection was refused by the server.

    You can use this Hercules utility to test connection.

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