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436 Miscellaneous
Global and advanced options in the Executive
Bias order table
The bias order table in a Merge or Diverge block’s Model Settings tabs displays each biasing Merge and Diverge block, its bias order, block label or name, mode, and Simulation Order.
• IftheblocksaresettoBiasorder:definedbySimulationOrder,thetablewillbeinacti- vated since bias order is determined automatically.
• IftheblocksaresettoBiasorder:eachblockdefinesitsown,thetableisactiveonlyin Merge or Diverge blocks in the Distributional, Priority, and Sensing modes. In blocks with those modes, it can be used to change the blocks’ bias order, as discussed above.
The Model Settings tab also reports the number of Bias blocks in the model; Bias blocks always have a higher bias order than any Merge or Diverge block.
Competing preferences
“Bias Order – resolving competing requests for flow” on page 395 discusses how competing preferences between Merge and Diverge blocks is resolved using Merge and Diverge blocks.
Global and advanced options in the Executive
The Executive block (Item library) oversees the global discrete rate system. It is responsible for calculating a model’s effective rates, centralizing and coordinating the information from Rate library blocks as discussed in the advanced topic “LP technology” on page 448.
The Executive’s Discrete Rate tab is used as a central location for setting options used through- out a discrete rate model. These options are divided into global and advanced options, as dis- cussed below.
Global options
The Executive’s global options are:
• Definingthe“infinite”rate
• Defining a “zero” effective rate
• Setting options for how often blocks should update their flow status
• ChoosingthattheValveanimateandreportblockingandstarvinginformation • Managingflowunits
The first three options are listed in a global options frame at the top of the tab (shown below); the fourth option is located at the bot- tom of the tab. They are all discussed in the fol- lowing sections.
Infinite rate
The Discrete Rate tab specifies that a rate equal
to or greater than some number is considered
infinite; the default setting is that a rate 1e10 is considered infinite. This information is important when setting critical constraints and for the determination of the effective rate. It is discussed fully in “Infinite rate” on page 372.
Zero effective rate
The Discrete Rate tab specifies that an effective rate less than or equal to some number is con- sidered zero, resulting in no flow. The default setting for that number is 1e-10. It is strongly
Global options in Executive
Discrete Rate

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