Page 453 - ExtendSim User Guide
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Mixing Flow and Items 427
Using the Interchange block to mix items with flow
Interchange block) where it is filled with cargo according to a filling rate. Once full, the ship sails for a period of time (represented by an Activity block) until reaching the new destination port (another Interchange block). At this point the ship’s cargo is unloaded according to the unloading rate.
To simulate the loading process, flow is piped from the Interchange block's inflow connector into the item/ship. Once filled, the item/ship exits the block, taking the flow with it. Con- versely, once the item/ship arrives at the second Interchange block, flow is piped from it into the second Interchange block's outflow connector.
The item/ship travels with a Quantity
attribute that has been set to a value of
1000. This attribute sets the ship’s capac-
ity. For the filling process, the Inter-
change releases the ship when it is full,
that is, after 1,000 units of flow have been piped in. The second Interchange block releases the ship when it is empty, that is, after 1,000 units of flow have been piped out. At the end of the simulation run, the ship has not yet been released from the unloading dock because it still con- tains 100 units of flow.
Yogurt Production model
The Yogurt Production model, located in the folder \Examples\Turorial\Discrete Rate and discussed in the Discrete Rate Tutorial that starts on page 332, is an example of using an Interchange block set to Tank only exists while item is in it.
Release options for unloading
In this model, empty item/pallets are generated ran-
domly by a Create block (Item library). The arrival of
an item/pallet causes the Interchange block to have
flow capacity; the maximum capacity of 24 cartons is
entered in the block’s dialog. Once the maximum
capacity is reached, the full pallet leaves the block. The Interchange block then has no capacity until another pallet arrives.
Yogurt Changeover model
This model is based on the Yogurt Production model from above. The Yogurt Changeover model, however, provides a period of time (the changeover) for an operator to remove each full pallet and replace it with an empty pallet, and there is an infinite supply of empty pallets.
In this model, each Create block (Item library)
can generate an infinite number of items so
that empty pallets are available as required.
Activity blocks (Item library) represent the two
minute changeover time. Once a pallet has
been released from an Activity, it notifies a
Gate block (Item library) to open, pulling in a pallet from the Create block. This process causes the Interchange to not have a new pallet/item to fill until the changeover from the previous pal- let is finished.
Yogurt Production palletization
Yogurt Changeover palletization
Discrete Rate

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