Emerson Exchange 365

What is the exact difference between the Unit Parameters and Recipe parameters?

Hello All,

What is the exact difference between the Unit Parameters and Recipe parameters?

when should we go with Unit parameters and When shoul we go with Recipe parameters?

Thanks in Advance.

 

 

manik

• 23 Feb 2015 7:34 PM
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2 Replies

• IntuitiveNeil

  

  • 23 Feb 2015 9:45 PM

  Unit Parameters are typically used for properties of the unit that don't change from product to product, as examples; vessel size, time needed to clean, maximum pressure or vessel material i.e. physical of logical properties of that particular unit. In a unit class based context similar units may be characterised with unit parameters which determine minor difference between unit instances. These unit parameter can then be used in procedural logic (phases, operations, unit procedures) to make run time decisions.
  
  Recipe parameter should be used to identify differences between different products or grades of a product. For example the quantities of ingredients, mix times, mix speeds, temperatures of reaction etc.
  
  I hope this brief description points you in the right direction.

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• Youssef.El-Bahtimy

  

  • 23 Feb 2015 10:06 PM

  If you haven't taken Emerson's courses on batch architecture, (http://www2.emersonprocess.com/en-US/brands/edservices/automationsystems/DeltaV/Pages/7016.aspx) it would be a good idea.

  Units and their parameters are persistent and exist in the controller.  Recipe parameters exist in the Batch executive's run-time batch runner processes, and only exist while the batch is running (though their historical values can be referenced in batch history, given the proper batch context).   Unit parameters can be referenced and changed by control logic and graphics at any time, while recipe parameters can not be referenced directly by controller logic or graphics (except Batch Control Active-X objects).

  Recipe parameters are pushed (downloaded) to phase batch parameters through deferral.  These phase batch parameters exist in the controller and can be referenced by the controller logic or graphics but only while the phase is loaded.

  Determination of when to use unit parameters vs. recipe parameters is dependant on your system and process architecture.  Since Unit parameters are not initialized from batch to batch, keeping track of a changing property of the unit or it's contents may be done there.  If you want to store information about how a batch should be processed, recipe parameters and formulas of recipe parameters are a much better idea.

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