Error when using "Retain State"

Tom_abc
Tom_abc Altair Community Member
edited October 2020 in Community Q&A

When I run it ('Error_Retain_State.vsm') only once or using 'Auto Restart', it can run successfully. However, if I further choose the 'Retain State', the model will produce an error called 'CVode-- Trouble interpolating at...'.

Can someone tell me why this error occurs? It seems a very simple example (only a variable and an integratrator) yet the error still occurs. Please see attached Vissim file.

 

<?xml version="1.0" encoding="UTF-8"?>Model1.png

<?xml version="1.0" encoding="UTF-8"?>Error1.png

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Answers

  • Ric_22025
    Ric_22025
    Altair Employee
    edited August 2020

    Hi Tom_abc

     

    Did you purposely set the integration type to BDF?  the error you are seeing is related to the settings you've chosen for BDF.  Try running your model with RK2 or RK4 and you should see the correct behavior with retain state.  

     

    Ric

  • Tom_abc
    Tom_abc Altair Community Member
    edited September 2020

    Yes I purposely chose the BDF method for the model. Thank you Ric, it now have no error message if we chose other methods. So does it means that we cannot 'retain state' if we use BDF method?