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Delaying Flow
Controlling a Valve’s maximum rate
quantity goal in this model, the changeover is controlled using a second Valve with a duration goal, rather than by an item.
Changeover With Only Goals model
Since it’s Flow Control tab specifies that it has an initial quantity goal of 5000 gallons, the Pro- duction Gate valve starts the simulation by observing its maximum rate setting – infinity. How- ever, as was true for the Changeover Quantity Goal model, the block’s actual effective rate will be impacted by the Liquid Supply and Fruit Supply valves upstream.
The Production Gate's goal state is communicated to the Changeover Gate through the connec- tion between the first block’s GS (goal status) output connector and the second block’s start input connector. Because of this connection and because of how the duration goal has been specified in the Changeover Gate, the duration goal starts in the Off state and will switch to On only after the Production Gate's quantity goal is completed. After 20 minutes, the Duration Goal is finished and the Changeover Gate sends a message to the Production Gate to start a new quantity goal.
☞ Unlike the Duration Goal model that allows flow to pass through for a specified amount of time, the duration goal in this model causes flow to be blocked for a certain period. The Changeover Gate’s maximum rate is set to 0 and the goal’s duration is set to 20 minutes. While the goal is On, the block’s maximum rate (0) is observed and no flow passes through, allowing for the changeover.
Discrete Rate

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