Page 440 - ExtendSim User Guide
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Delaying Flow
Convey Flow block
A Convey Flow block is computationally intensive, so it should be used only if the system you are modeling requires very precise tracking of flow movement and position. For instances when the block should not be used, see page 417.
Dialog settings
Movement of flow across the Convey Flow block is influenced by the dialog settings and parameters.
Determining speed and distance
The Convey Flow block offers two options: Speed determines travel time or Delay determines travel time. Depending on which of these is selected, the following entries can be made:
• Speed. Specifies the
maximum potential
speed at which the
conveyor can trans-
port flow. However, when the potential supply of flow from the conveyor exceeds the down- stream demand, the observed speed of the flow can become something less than the speed parameter.
• Delay.Representstheamountoftimeflowwillspendintheblockifthereisnodownstream blocking. If the block’s dialog is set to Speed determines travel time, the delay is calcu- lated by dividing Length by Speed. If the dialog is set to Delay determines travel time, the flow will take the entered Delay time to travel the stated Length.
• Length.Representsthedistanceflowmusttravelbeforereachingtheblock'sexitpoint.The length of a Convey Flow block has to be greater than 0.
• Maximum density. Density is the amount of flow that has accumulated at any one point on the conveyor. The observed density of flow on a conveyor is a function of the upstream sup- ply rate, the conveyor's speed, the downstream demand rate, and what settings have been chosen in the block’s dialog. The Maximum density setting limits how high the pile of flow can be at any one point along the conveyor. For example, if the upstream supply rate is greater than or equal to the conveyor's maximum inflow rate (speed*maximum density), then the amount of flow entering the conveyor will be equal to the maximum density. In this case, it is the conveyor's capacity to receive flow that limits its effective inflow rate.
☞ The parameters for speed or delay can vary dynamically during the simulation; the length and maximum density parameters remain fixed.
Convey Flow behavior
The Convey Flow block is divided into segments, where the boundaries of each segment are defined by a change in the density of flow. Depending on the options chosen in the dialog, flow
Dialog parameters for Convey Flow
Discrete Rate

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