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deltav ,the strange question.

Hi to All,

In Delta-V, when the deltav workstation is restarted by itself,some parameter is initialized. for example,the anto-mode becomes handle-mode.

 Anyone have some idea.?

6 Replies

  • Leo, Are you talking about an Application Station running control modules in the virtual controller?

    When the virtual controller restarts, it must load its control modules from the download files.  During initialization of the modules, parameters will be set to their default values, unless there is some initialization to restore them to a more current value.

    Typically, the virtual controller is used to hold data from external sources, or to perform supplementary calculations on process data where it is preferred that the controllers do not perform these calculations.  We use the virtual controller mainly for integration with supervisory applications.  

    Unlike real controllers, the virtual controller does not have Non volatile Memory to preserve runtime values on a restart..  

    So is this particular module appropriate for the virtual controller or should it be run in a real controller?

    Do you have any initialization logic that could set the MODE to the correct setting when the station restarts?

    Is the Mode a value that comes from a remote OPC server?  

    If you can, add an initialization routine to the module such that when it restarts, it can determine what the correct mode should be and automatically set it.  The default value and status of any parameters that need initializing should be set so that downstream logic does not take action until the values have been initialized.  For instance the Status should be set to BAD as the default and then set to GOOD once the value has been initialised.  

    There are many ways to approach this, but the bottom line is that when the workstation restarts, it loads the modules from the download scripts and they will do exactly what you configure them to do.

  • In reply to Andre Dicaire:

    Andre,thanks.you are so helpful.how can I discover the virtual controller.I will have a try.I think it's not about   the virtual controller.because it didn't appear before.I hear from the operator who met several times.

  • In reply to Leo He:

    Leo,  I have no idea at this point what your issue is.  A reboot/restart of a DeltaV Operator station does not affect the mode of any control module or any other parameter, unless you have configured logic to do so.  I don't know what you mean by "parameter goes from Auto-Mode to Handle-Mode".  Is this a user defined parameter in a control module?  If so, it will not change unless there is logic to do so.  

    If the Workstation is indeed writing to a parameter during a restart, this should be captured in the Event Chronicle as a parameter change.  The event will show the worstation name where the write took place.  If you have a VBA script in DeltaV Operate that is running on restart, this write would be captured as an event.

    If you have logic in the controller that somehow monitors the presence of the workstation, than you should be able to find this using DeltaV explorer to find "References" to the module with the parameter.  Right click on the module and in the menu select "references". A dialog will appear listing all the references to this module, and this would show which module is referencing this parameter.

    Other than that, I cannot think of what your issue might be.

  • Well just thinking out of box
    The workstation which you are restarting, is it assigned ad the master time sync server? If so please check the ntp status of that controller where your module is assigned it should b good when u restart!
  • In reply to bobgally:

    Thanks to all help.I need more advice.The more,the better.The mode is from  the PID module.I am sorry i speak uncleanly.Do the virtual controller need the special licenses.

  • In reply to Leo He:

    Just to help you understand - the virtual controller is actually the workstation itself processing the logic modules that you create in Control Studio and then assign and download to a workstation (if you do not have controllers).  I think to properly operate an offline development system that you will need at least a base station license and perhaps one of the Simulate versions.