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      <div class="title_topic3" id="xps10_pagetitle">Flow direction overview</div>
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               <p class="para_td">Overview</p>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('routingtools/assign_flow.html');return(false);">How To</a></p>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('routingtools/flow_design.html');return(false);">Related Topics</a></p>
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      </table><br><p class="para_topic">Flow direction is determined by the definition of a run. Flow is always away from a <b class="uiTerm">From Item</b> and towards a <b class="uiTerm">To Item</b>. Ports may have flow direction assigned to them, such that flow is limited to being into or out of a port. If a port is defined to have flow going in, that port cannot be defined as the <b class="uiTerm">From Port</b> of a <b class="uiTerm">From Item</b>. Conversely, if a port is defined to have flow going out, that port cannot be defined as the <b class="uiTerm">To Port</b> of a <b class="uiTerm">To Item</b>.
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      <p class="para_topic"><b class="uiTerm">Flow Direction</b> is determined by the system when a run is defined by assigning flow to the segments of the run, where possible. If flow direction cannot be determined automatically, flow direction may be assigned manually. If a <b class="uiTerm">From</b> or <b class="uiTerm">To Item</b> of a Run is defined as a Virtual Item, flow is not determined.
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      <p class="para_topic">If a flow sensitive component is placed onto a segment with flow assigned, the only placement solutions are those that do not contradict flow direction. If flow sensitive components exist in the run that contradict the flow direction assigned to the segments, a <b class="uiTerm">Design Rule Violation</b> is created. A component is considered flow sensitive if one or more of its ports have <b class="uiTerm">Flow Direction</b> (In or Out) assigned.
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      <p class="para_topic"><b class="uiTerm">Flow Direction</b> is shown by temporary <b class="uiTerm">Flow Indicators</b> along segments to which flow direction is assigned. Additionally, permanent <b class="uiTerm">Flow Arrows</b> may be placed onto segments, usually done in <b class="uiTerm">Logical</b> diagrams.
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      <div class="title_division">Flow direction algorithm</div>
      <p class="para_division">The algorithm that automatically determines flow direction is based on the definition of a run. If a section of a routing system is not part of a run, no flow direction exists in that section. &nbsp;When a run is defined or edited, the <b class="uiTerm">Flow Direction Algorithm</b> assigns flow direction to each segment of the run, where possible.
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      <p class="para_division">A run, by definition, has at least one <b class="uiTerm">From Item</b> and one <b class="uiTerm">To Item</b>. The flow direction in a stock connected directly to a <b class="uiTerm">From Item</b> is always away from the Item. The flow direction in a stock connected directly to a <b class="uiTerm">To Item</b> is always towards the Item.
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      <p class="para_division">Flow direction does not change at a point in which there are only two directions possible. Therefore, where two segments meet and one has flow assigned the flow direction of the other segment must be the same direction as the first. If more than two segments meet at a point and two or more of them do not have <b class="uiTerm">Flow Direction</b> assigned, flow direction cannot be further determined.
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      <div class="title_division">Flow indicators</div>
      <p class="para_division">The direction of flow is displayed as temporary markers for quick reference.</p>
      <p class="para_division">Flow Indicators are presented as cone markers at the midpoint of all linear segments for which flow direction is assigned. By using a cone head, rather than a flat arrow, the direction of flow is indicated regardless of the view orientation (Top, Front, Left, Isometric, etc.).</p>
      <p class="para_division">Flow Indicators are displayed by choosing the <b class="uiTerm">Show Flow</b> option of the right&ndash;click menu in the <b class="uiTerm">Run Navigator</b> when a run is selected. Indicators appear on the segments of all selected runs.
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      <p class="para_division">The image below shows a simple run with <b class="uiTerm">Show Flow</b> active, in a Routing Mechanical model.
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      <p align="center"><img align="bottom" src="graphics/flow1.gif"></p>
      <p class="para_division">The position and orientation of the cone is determined by the segment. The tip of the cone is positioned at the segment center point and the base of the cone is centered along the segment.</p>
      <p class="para_division">Segments that do not have flow direction assigned display double opposing coneheads, as shown below.</p>
      <p align="center"><img align="bottom" src="graphics/flow3.gif"></p>
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