RasPi as a modbus slave

svantuil
2015-03-25
2017-02-19
  • svantuil - 2015-03-25

    I am currently attempting to connect Ignition SCADA OPC server to the Pi as a modbus tcp slave. I can read the registers beautifully, however when I write to a register, it resets itself after about a second.
    I have tried modbus slave simulators, other devices, and a Wago head unit running CoDeSys 2.3, and they all work correctly.

    I have tried running with a blank program to verify that the POU wasnt doing something silly.
    Is there any settings I am missing in 3.5 SP6 that could be resetting the values?

    Thank you.

     
  • eschwellinger

    eschwellinger - 2015-03-25

    Hi,

    you need to increase or remove the timeout see screenshot.

    BR
    Edwin

    IMG: ModbusSlaveTimeout.jpg

     
  • svantuil - 2015-03-26

    Days of pulling out my hair, over a checkbox.
    Thats fixed it.

    Thank you for your help Edwin.

     
  • d.langhojer - 2016-10-16

    Hi.

    I have a wago 8203 as unit for my gate and now i want to use the raspi for the buttons to control it from the house.

    but I gave up because I don't understand how the thing with the registers works.
    Does anyone somehow have a (both) project where the raspi simpli gets 4 outputs from variables out of an working wago project and where the raspi sends 4 inputs to the wago project?

    I just want my hardware buttons be able to be lightet when the gate is not closed.

    AND!: I don't know why this way with 4 inputs and 4 outputs isn't used anyway as remote-buttons over ethernet.....

     
  • eschwellinger

    eschwellinger - 2016-10-16

    Hi,
    are you using wago 8203 with CODESYS V3 or V2.3?

    BR
    Edwin

     
  • Irden - 2017-02-19

    I have a problem with ModbusTCP_Slave_Device on RPi3 - during program execution there is always message "The bus is not running".
    How can I turn ModbusTCP_Slave on?

    Runtime version 3.5.10
    Version of Ethernet and ModbusTCP_Slave_Device 3.5.10.0 too.

    IMG: scr1.PNG

     

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