View source for IS:macroscopicNode

{{ElementDocu|
elementName = macroscopicNode

|parent = {{IS:Tag|trackBegin}}, {{IS:Tag|trackEnd}}
|childs=''None''
|inheritedAttributes=''None''
|ownAttributes =

{{InheritRef
|attributeName = ocpRef
|contextLink = {{IS:Tag|ocp}}
|notes_en = 
}}

* {{Attr|flowDirection}}: This specifies how trains can pass the node. Possible values are:
:* {{Enum|in}} only into the node (track --> node)
:* {{Enum|out}} only out of the node (track <-- node)
:* {{Enum|both}} into and out of node (track <--> node)
:* {{Enum|unknown}} is restricted to a certain direction, but this direction is not known.
:* {{OtherEnum
|notes_en =
|notes_de =
}} {{AddAnn|| }}

|semantics =
A {{IS:Tag|macroscopicNode}} represents a logical connection of (multiple) {{IS:Doc|track}}s without respect to the physical layout of their {{IS:Doc|connections}}. {{AddAnn|| }}

|notes =
Many simulation programs, especially in the simulation domain for complete networks, have no knowledge about the physical {{IS:Doc|track}} layout of a station. They model a station as a "zero-dimensional vertex" in a "graph" with {{TT:Doc|train}}s being able to switch to every "edge" (here: {{IS:Doc|track}}) that is connected to that "vertex". The {{IS:Tag|macroscopicNode}} provides means to represent this simplified infrastructure model in {{rml}}.

Simulation programs that depend on precise "microscopic" modelling of stations (including {{IS:Doc|switch}}es, lengths, {{IS:Doc|signal}}s, ...) are likely to be troubled by {{IS:Tag|macroscopicNode}}. Possible solutions can be:

* refuse the import of XML-files containing {{IS:Tag|macroscopicNode}}

* convert the {{IS:Tag|macroscopicNode}} internally into a set of {{IS:Doc|switch}}es and thus allowing all travel directions as the {{IS:Tag|macroscopicNode}} does. This might severely mess up the {{IS:Doc|infrastructure}} model in case of {{IS:Tag|macroscopicNode}}s with many connected {{IS:Doc|track}}s.

* convert the {{IS:Tag|macroscopicNode}} internally into {{IS:Doc|openEnd}}s and thus allowing {{TT:Doc|train}}s to enter and leave the simulation in that point. "Warping" {{TT:Doc|train}}s from one {{IS:Doc|track}} of the node to another via "virtual open ends" is a semantically identical behaviour compared with a macroscopic node. {{AddAnn|| }}

|constraints =
*{{constraint|ocpRef|rml|tGenericRef|required}}
*{{constraint|flowDirection|rml|tFlowDirection|default=both}}

All {{IS:Doc|track}}s connected to this {{IS:Doc|macroscopicNode}} shall refer to the same {{IS:Doc|ocp}}.

The associated {{IS:Doc|ocp}} shall have suitable operational attributes set (e. g. as a station). {{AddAnn|| }}
|example=
Consider the {{rml|2.3}} example of {{site|1=https://www.railml.org/en/user/exampledata.html?file=files/download/exampledata/090318_Bahnkonzept_ExampleDataGPSinfradat_NorthUpperRhineNetworkRailML23.zip|2=Middle Rhine Railway by GPSinfradat}}.

[[File:mip1.png|347x305px]]

<nowiki />
{{IS:trackEnd/tab}}
<nowiki />

This code example defines a [[IS:trackBegin|track begin]] that is a [[IS:macroscopicNode|macroscopic node]].

<syntaxhighlight lang=xml>
<trackBegin id="tB35113" pos="0" absPos="-110">
  <macroscopicNode ocpRef="ocpFBGK"/>
</trackBegin>
</syntaxhighlight>

Consider the {{rml|2.2}} example of {{site|1=https://www.railml.org/en/user/exampledata.html?file=files/download/exampledata/130416_iRFP_ExampleDataFBS_EastSaxonyRailML.zip|2=East Saxony railway network by FBS}}].

[[File:mip3.pdf|623x210px]]

This code example defines a [[IS:trackBegin|track begin]] that is a [[IS:macroscopicNode|macroscopic node]].

<syntaxhighlight lang=xml>
<trackBegin id='trn_DN_80.6212_1' pos='0' absPos='102100'>
  <macroscopicNode ocpRef='ocp_DN'/>
</trackBegin>
</syntaxhighlight>
}}