User:RailML Coord Documentation/IS:balise

Introduction

Relation between railML^® elements <baliseGroup> and <balise>

In balise based ATP systems, each <balise> belongs to a <baliseGroup>.

Consequently, for balise based ATP systems, there are two levels of description: the higher level balise group, which is presented by the railML^® element <baliseGroup> and the more detailed level balise, presented by the railML^® element <balise>.

Usually, the definition of balise groups in the track layout is sufficient for the most purposes and it is not necessary additionally to give information about each balise of a balise group, because all relevant information for the ATP software engineering can be derived from the element <baliseGroup>. For example, all variables required for an ETCS balise telegram header according to SUBSET-026 (versions 2.3.0, 3.4.0 or 3.6.0), section 8.4.2.1, can be calculated from the information given by element <baliseGroup>.

Nevertheless, railML^® provides the possibility to specify each balise of a balise group, which can make sense in cases where the exact location of each balise in a balise group is important, for example for special test purposes or for the mounting and installation of the balises.

Conclusion:

The use of railML^® <balise> elements is optional.

But if railML^® <balise> elements are used, then the railML^® <baliseGroup> elements are mandatory. Each <balise> element must reference a <baliseGroup> element.

Concept of the railML^® element <balise>

Correspondent to the concept of railML^® element <baliseGroup>, also the railML^® element <balise> is suitable for all balise based ATP systems. This means, a railML^® element <balise> can be a KVB balise, an Ebicab balise, a RSDD balise (together known as KER balises) or a Eurobalise.

The general information provided for all hardware types of balises is:

• the location of the balise (using sub-element <spotLocation>)
• to which balise group the balise belongs to (using @belongsToBaliseGroup)
• the distance to the predecessor balise within the group (using @distanceToPredecessorBaliseWithinGroup)

In case of Eurobalise, the optional sub-element <isEurobalise> shall be used to specify the ETCS related information:

• the value of UNISIG variable N_PIG (provided in railML^® by @positionInGroup), which is defined by UNISIG in SUBSET-026 (versions 2.3.0, 3.4.0 or 3.6.0), section 7.5.1.81
• the value of UNISIG variable M_DUP (provided in railML^® by @duplicate), which is defined by UNISIG in SUBSET-026 (versions 2.3.0, 3.4.0 or 3.6.0), section 7.5.1.63 and
• the value of UNISIG variable M_VERSION (provided in railML^® by @mVersion), which is defined by UNISIG in SUBSET-026 (versions 2.3.0, 3.4.0 or 3.6.0), section 7.5.1.79

Best Practice / Examples

Example 1 – Eurobalises belonging to a Eurobalise group consisting of 2 fix data balises

This example shows the balise elements belonging to the ETCS balise group presented in Example 1 of railML^® element <baliseGroup>.

Example 1 – Balise group of 2 fix data balises

Corresponding railML^® description

<balises>

  <balise id="bg1_bal0" type="fixed" belongsToBaliseGroup="bg1" 
		distanceToPredecessorBaliseWithinGroup="0.0">
    <name name="127-00777-0" description="etcsName" language="EN"/>
    <spotLocation id="bg1_bal0_sloc01" netElementRef="ne_101" 
		applicationDirection="both" pos="45.0">
      <linearCoordinate positioningSystemRef="lps01" measure="100045.0"/>
    </spotLocation>
    <isEurobalise positionInGroup="0" duplicate="no" mVersion="32"/>
  </balise>

  <balise id="bg1_bal1" type="fixed" belongsToBaliseGroup="bg1" 
		distanceToPredecessorBaliseWithinGroup="3.0">
    <name name="127-00777-1" description="etcsName" language="EN"/>
    <spotLocation id="bg1_bal1_sloc01" netElementRef="ne_101" 
		applicationDirection="both" pos="48.0">
      <linearCoordinate positioningSystemRef="lps01" measure="100048.0"/>
    </spotLocation>
    <isEurobalise positionInGroup="1" duplicate="no" mVersion="32"/>
  </balise>

<balises/>

Example 2 – Eurobalises belonging to a Eurobalise group consisting of 1 fix data balise and 1 controlled balise

This example shows the balise elements belonging to the ETCS balise group presented in Example 2 of railML^® element <baliseGroup>.

Example 2 – Balise group of 1 fix data balise and 1 controlled balise

Corresponding railML^® description

<balises>

  <balise id="bg1_bal0" type="fixed" belongsToBaliseGroup="bg1" 
		distanceToPredecessorBaliseWithinGroup="0.0">
    <name name="127-00777-0" description="etcsName" language="EN"/>
    <spotLocation id="bg1_bal0_sloc01" netElementRef="ne_101" 
		applicationDirection="both" pos="45.0">
      <linearCoordinate positioningSystemRef="lps01" measure="100045.0"/>
    </spotLocation>
    <isEurobalise positionInGroup="0" duplicate="no" mVersion="32"/>
  </balise>

  <balise id="bg1_bal1" type="fixed" belongsToBaliseGroup="bg1" 
		distanceToPredecessorBaliseWithinGroup="3.0">
    <name name="127-00777-1" description="etcsName" language="EN"/>
    <spotLocation id="bg1_bal1_sloc01" netElementRef="ne_101" 
		applicationDirection="both" pos="48.0">
      <linearCoordinate positioningSystemRef="lps01" measure="100048.0"/>
    </spotLocation>
    <isEurobalise positionInGroup="1" duplicate="no" mVersion="32"/>
  </balise>

<balises/>

Example 3 – A Eurobalise belonging to an Eurobalise group consisting of 1 fix data balise

This example shows the balise elements belonging to the ETCS balise group presented in Example 4 of railML^® element <baliseGroup>.

Example 3 – Balise group of 1 fix data balise

Corresponding railML^® description

<balises>
  <balise id="bg4_bal0" type="fixed" belongsToBaliseGroup="bg4" 
		distanceToPredecessorBaliseWithinGroup="0.0">
    <name name="127-00727-0" description="etcsName" language="EN"/>
    <spotLocation id="bg4_bal0_sloc01" netElementRef="ne_104" 
		applicationDirection="both" pos="210.0">
      <linearCoordinate positioningSystemRef="lps01" measure="103210.0"/>
    </spotLocation>
    <isEurobalise positionInGroup="0" duplicate="no" mVersion="16"/>
  </balise>
<balises/>

Additional Information

Open Issues

If the general information provided by the railML^® element <balise> is not sufficient for a KER balise application, then please open a request in the railML^® forum – https://forum.railml.org (link to the railML^® website) – reporting the missing information to be modelled in railML^®. railML^®.org will provide a suggestion for modelling the missing information in railML^®, for example added by a new optional sub-element railML/infrastructure/functionalInfrastructure/balises/
balise/isEbicabBalise which includes the new requested information.