Page 153 - ExtendSim User Guide
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Items, Properties, and Values 127
Item properties
this attribute has been properly configured, the blocks referencing the CarType attribute will display the strings “Ford”, “Toyota”, or “Volvo” instead of the numbers 1, 2, and 3.
• ThevalueofaDBaddressattributecontainsasinglevaluethatrepresentsalocationor address in a database. This address is composed of four separate numbers, where each num- ber is an index for an ExtendSim database, table, field, and record. Taken together, the num- bers target a specific location in the database. (Incomplete DB addresses are allowed. For example, an item may have a DB address attribute with only the database and table indexes defined.)
In addition to item attributes, the Rate library blocks of ExtendSim AT and Suite have two types of flow attributes. These are discussed starting on page 353.
☞ The value of a DB address attribute cannot be used directly. It must be “decoded” using a Get. Read(I), or Write(I) block or by accessing DB attribute functions in one of the equation-based blocks.
Using item attributes
The following table lists some common attribute-based modeling activities and the blocks that are usually used to facilitate them. All blocks are from the Item library.
To Do This:
Initialize newly created items with attributes
Define default attributes for item resources Set or modify values for existing attributes Check attributes on existing items
Route items based on attributes
Sort and release items from queues based on attri- butes
Sort items based on attribute values and condition- ally release them based on an equation
Pull in items and batch them based on attribute val- ues
Use attribute values to specify a delay or processing time
Define the value/string correspondence for item string attributes
Find which block uses an attribute
Managingattributesandtheirnames,suchasrenam- ing or deleting an attribute
Use Block(s)
Create (when “Create items by schedule” is the selected behavior)
Resource Item
Set, Equation(I), Queue Equation
Any property-aware block; see the table on page 121.
Select Item Out (when “Select output based on attribute” is chosen)
Queue (when it sorts by attribute value), Queue Matching
Queue Equation
Batch (when “Match items into a single item” is the selected behavior)
Activity (when “Delay is: an item’s attri- bute value)
Executive (Item Attributes tab in “Declare string attribute values” mode)
Executive (Item Attributes tab in “Manage all attributes” mode)
Executive(ItemAttributestabin“Manage all attributes” mode)
Discrete Event

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