Home » railML newsgroups » railml.common » [railVIVID 2.2.0 beta 1] checking semantic constraint IS:023
[railVIVID 2.2.0 beta 1] checking semantic constraint IS:023 [message #4051] Wed, 17 June 2026 14:22 Go to next message
Mathias Vanden Auweele is currently offline  Mathias Vanden Auweele
Messages: 164
Registered: February 2025
Location: Brussels
Senior Member
Hello,

I think there is an issue with the implementation of semantic constraint IS:023

Our railML files has this LPS:
        <linearPositioningSystem id="_ips" startMeasure="0" endMeasure="-1" linearReferencingMethod="absolute" units="metres">
          <name name="Intrinsic linear positioning system" language="en" description="This LPS is used for defining measuring tape distances on NetElements." />
          <isValid from="2000-01-01" />
        </linearPositioningSystem>

Note the endMeasure="-1".

All the linear coordinates that we use in our file that refer to this LPS, are marked as violating the IS:023 by railVIVID.

We have implemented based on the presentation given by Christian at the 46th conference where the internal positioning systems were introduced and more specifically on the slide with this title:
#541 Positioning approach (3/26)

Here's an extract of the slide:
Quote:

Intrinsic positioning system:
• This is a <linearPositioningSystem> with
• @startMeasure=0.0
• @endMeasure={infinity} → use value „-1" (because real pos values must not be negative)
• @units=metres
• @linearReferencingMethod=absolute
So we assume that "-1" is a valid value for "endMeasure" in our use case. Does railVIVID take this into account?

We notice that the wiki documentation doesn't show this -1. https://wiki3.railml.org/wiki/RTM:linearPositioningSystem

Which is probably the reason why this exception was not implemented in railVIVID.

If this -1 exception is still possible, I propose to implement it in railVIVID and make a note about this in the attribute on the wiki.

Thanks!

Mathias Vanden Auweele
Railway data freelancer
https://matdata.eu
Brussels, Belgium

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Re: [railVIVID 2.2.0 beta 1] checking semantic constraint IS:023 [message #4080 is a reply to message #4051] Tue, 07 July 2026 12:40 Go to previous messageGo to next message
Marharyta Vyskarka is currently offline  Marharyta Vyskarka
Messages: 26
Registered: April 2025
Junior Member
Hello Mathias,

Thank you for your feedback! We will investigate this issue further, however any solution if approved will be introduced after the release of 2.2.0-final that is under development this month. Christian is currently on vacation and we would need to clarify some details with him.

I will provide an update closer to the end of August, because then the coordinators should be available to discuss this issue.

Sincerely,
Margo Vyskarka

Marharyta Vyskarka – Software Developer
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org

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Re: [railVIVID 2.2.0 beta 1] checking semantic constraint IS:023 [message #4150 is a reply to message #4080] Fri, 04 September 2026 10:33 Go to previous messageGo to next message
christian.rahmig is currently offline  christian.rahmig
Messages: 577
Registered: January 2016
Senior Member
Dear Mathias,

thank you for discovering this inconsistency between semantic constraint IS:023 and positioning approach for railML 3.3.

We discussed this topic with all coordinators. It was decided to keep the semantic constraint and adapt the positioning approach. So, the @endMeasure value "-1" will not be allowed anymore. I am going to inform you when the positioning approach will be updated.

Best regards
Christian

Christian Rahmig – Infrastructure scheme coordinator
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org

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Re: [railVIVID 2.2.0 beta 1] checking semantic constraint IS:023 [message #4151 is a reply to message #4150] Fri, 04 September 2026 10:56 Go to previous messageGo to next message
christian.rahmig is currently offline  christian.rahmig
Messages: 577
Registered: January 2016
Senior Member
Dear all,

following the decision to not allow for @endMeasure value "-1" I updated the slides with the railML 3.3 positioning approach best practices [1].

[1] https://cloud.railml.org/f/801516

Best regards
Christian

Christian Rahmig – Infrastructure scheme coordinator
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org

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Re: [railVIVID 2.2.0 beta 1] checking semantic constraint IS:023 [message #4154 is a reply to message #4151] Fri, 04 September 2026 13:24 Go to previous messageGo to next message
Thomas Nygreen is currently offline  Thomas Nygreen
Messages: 125
Registered: March 2008
Senior Member
Dear all,

I believe both the old -1 and the new
@endMeasure = (to be set later analyzing all the netElements where
this linear positioning system is being used for their longest length)
illustrate perfectly that this attribute does not provide additional value, and should simply be made optional, along with @startMeasure. The only reason I see to keep them at all is that a regular linear positioning system may have defined minimum and maximum values that are kept as properties of the positioning system itself, and that information may need to be exchanged. If no one has such a need, they could also be removed, along with the semantic constraint. Aggregating the maximum (and minimum) value and putting it in the file goes against our rule to avoid duplicate information.

Best regards,
Thomas

Thomas Nygreen – Common Schema Coordinator
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org

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Re: [railVIVID 2.2.0 beta 1] checking semantic constraint IS:023 [message #4159 is a reply to message #4154] Fri, 04 September 2026 22:31 Go to previous messageGo to next message
Mathias Vanden Auweele is currently offline  Mathias Vanden Auweele
Messages: 164
Registered: February 2025
Location: Brussels
Senior Member
I agree with Thomas, thank you!

Mathias Vanden Auweele
Railway data freelancer
https://matdata.eu
Brussels, Belgium

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Re: [railVIVID 2.2.0 beta 1] checking semantic constraint IS:023 [message #4165 is a reply to message #4159] Mon, 07 September 2026 08:27 Go to previous message
Dominik Looser is currently offline  Dominik Looser
Messages: 62
Registered: March 2020
Member
Hi all,

I agree with Thomas that @startMeasure and @endMeasure can be made optional or even removed. We do not need the information.
So far, we have used @endMeasure = -1 to identify the relative/intrinsic positioning system, because in earlier positioning approach versions, all linear positing systems had "@linearReferencingMethod=absolute".
Now I see that the @linearReferencingMethod for the relative positioning system is supposed to be "relative", which I support.

(Altough, to support legacy files, we still have to check the @endMeasure=-1 value as well.)

Best regards,
Dominik Looser

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