National values

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As National values (engl. National values ) are in a European Train Control System ETCS a set of parameters referred to with which the behavior of the system to the specific requirements of an infrastructure operator is adjusted. Among other things, they have an impact on localization as well as path and speed monitoring , on braking curves the approach to "stop" signals , fault reactions and command runs .

The ETCS specification describes national values ​​as “values ​​that are transmitted to a train when it enters the infrastructure of an infrastructure operator and that reflect its rules and regulations. National values ​​can be changed at any time in the area of ​​the infrastructure operator. "(" Values ​​that are transmitted to a train when entering the infrastructure of an administration related to rules and regulations of that administration. National values ​​may be changed within an administrations area. ") ETCS behaves differently in every country.

The current ETCS specification ( Baseline 3 Release 2 / SRS 3.6.0 ) defines 35 national values. These are summarized in a list of national values (“set of national values”).

Handling the list

The list of national values ​​is transferred from the route to the train using the ETCS data package 3 (“Packet Number 3”), via Eurobalise or RBC , and saved on the vehicle. Previous values ​​for national values ​​will be overwritten. One or more area IDs (NID_C) are part of the list. The package 3 has a size of at least 256 bits, with optional additional area identifiers (NID_C) and optional correction factors of the lambda brake model can lead to a larger amount of data .

The list must be complete and can be updated at any time. It applies to all ETCS levels .

New national values ​​are transferred for cross-border journeys. When passing between two RBCs, the transferring RBC can request route-related information from the accepting RBC, including national values.

When changing the ETCS operating mode , national values ​​remain unchanged in most cases. That applies u. a. for shutdowns that involve switching to the standby (SB) or no power (NP) operating modes . If an ETCS trip is ended in levels 0 to 3 , the national values ​​of the previous trip are used at the start of a new trip (start of mission).

The list is only discarded when the operating mode is changed after a system error (SF) or isolation (IS). It is also deleted if the list for a country or region identifier (NID_C) read by a balise group is not contained in the scope of the list of national values. In this case, standard values ​​stored on the vehicle are used.

The standard values ​​are also used if no national value is available. Such a gap can arise if ETCS track and vehicle equipment have different system versions and individual national values ​​of the vehicle were not transferred from the track as a result.

planning

When defining ETCS projects, the client must prepare a complete list of national values. Values ​​must also be specified for parameters for which the standard value of the ETCS specification is to apply unchanged.

Others

Correction factors are transferred as national values ​​in order to map the safety margins that are usual when setting up pre-signals , where between 10 and 50 percent are usually added to the braking distance when calculating the braking distance, depending on the infrastructure operator. In the longer term, the aim is to standardize the safety margins, according to which the corresponding national values ​​could be omitted.

When changing to Level 2 in Germany, the national values ​​are transmitted on the entry signal.

literature

  • Richard Kahl: ETCS Level 2 . In: Jochen Trinckauf , Ulrich Maschek, Richard Kahl, Claudia Krahl (eds.): ETCS in Germany . 1st edition. Eurailpress, Hamburg 2020, ISBN 978-3-96245-219-3 , pp. 203 f . (List of national values ​​in the Deutsche Bahn network)

Web links

Individual evidence

  1. a b ETCS specification , subset 023, version 3.3.0, section 4.
  2. Michael Leining: Is ETCS an interoperable system? The plea for a clear yes and no! In: signal + wire . tape 104 , no. December 12 , 2012, ISSN  0037-4997 , p. 6-10 .
  3. ETCS specification , subset 026, version 3.6.0, A.3.2.
  4. a b c ETCS specification , subset 026, version 3.6.0, 7.4.2.1.1.
  5. a b c d Norbert Apel, Jenny Strahl: Basic principles of Odometry . In: Peter Stanley (Ed.): ETCS for engineers . 1st edition. Eurailpress, Hamburg 2011, ISBN 978-3-7771-0416-4 , pp. 126-130 .
  6. ETCS specification , subset 026, version 3.6.0, 3.18.2.9.
  7. ETCS specification , subset 026, version 3.6.0, 3.18.2.3.
  8. a b c Karin Löfstedt: Opening Scenarios . In: Peter Stanley (Ed.): ETCS for engineers . 1st edition. Eurailpress, Hamburg 2011, ISBN 978-3-7771-0416-4 , pp. 72-89 .
  9. ETCS specification , subset 026, version 3.6.0, 3.15.1.2.3
  10. a b ETCS specification , subset 026, version 3.6.0, 4.10.
  11. ETCS specification , subset 026, version 3.6.0, 3.18.2.7.
  12. a b c ETCS specification , subset 026, version 3.6.0, 3.18.2.4/5.
  13. ETCS specification , subset 026, version 3.6.0, 3.18.2.10.
  14. ETCS specification , subset 026, version 3.6.0, 3.18.2.6.
  15. Norbert Apel, Jenny Strahl: Engineering for trackside projects in Level 1 . In: Peter Stanley (Ed.): ETCS for engineers . 1st edition. Eurailpress, Hamburg 2011, ISBN 978-3-7771-0416-4 , pp. 273-276 .
  16. Peter Woodbridge: Lineside engineering for level 2 . In: Peter Stanley (Ed.): ETCS for engineers . 1st edition. Eurailpress, Hamburg 2011, ISBN 978-3-7771-0416-4 , pp. 279-283 .
  17. Peter Eichenberger, Olaf Gröpler: ETCS braking curves in Europe (=  ZEVRail conference proceedings SFT Graz . Volume 129 ). 2005, ISSN  1618-8330 , ZDB -ID 2072587-5 , p. 266-274 .
  18. On the way to the digital hub Stuttgart: the technology. (PDF) In: bahnprojekt-stuttgart-ulm.de. Deutsche Bahn, 2020, p. 6 in PDF , archived from the original on January 3, 2020 ; accessed on January 3, 2020 .