Scenarios

Introduction

The Post T / Stellwerk Simulation Series applications contain a powerful system for specifying and configuring simulations. Scenarios can be written to specify any number of and in any combination, the following:

• Initial Panel State (switch positions, danger labels, switchkey positions)
• Trains that already exist in a yard
• Trains that will enter the yard at a future time
• Expert Option overrides
• Engineering Works – track possessions and earthing of catenary
• Panel defects

In addition, support for custom timetables is included. This allows for a large degree of customizability as not only train schedules be defined, but train composition and physics can be specified as well.

The scenario system is by no means complete – there are some limitations but many situations can be modeled for a variety of goals.

File Structure

Each scenario is defined in a file named scenario.xml. This file is placed in a folder, which is placed in the user's scenarios folder. Additional materials are normally referenced via an html file which acts as an index of additional resources. It is this file that is launched when the user presses the “View Additional Resources” button in the scenario launcher window. The directory structure is summarized below:

• scenarios

• MyScenario

• scenario.xml
• <myAdditional_info_en.html>
• <myAdditional_info_nl.html>
• <myAdditional_info_de.html>
• < other files >

The scenario.xml file is obviously mandatory – the others are not. The additional info html files would normally reference any other files – PDFs, movies, etc. Since the simulation supports three languages; scenario.xml optionally points to three html files which can be used for English, Dutch and German speakers.

Scenario Structure

A scenario is completely defined in a single XML file.

File Header

Each scenario begins with the following statement:

<?xml version="1.0" encoding="ISO-8859-1"?>

This defines helps the XML parser to parse the file, as it knows the version and encoding format of the file.

Comments

Comments are allowed and recommended within XML documents. The following is an example of a comment:

<!-- This is a comment.-->

Comments are used in this document to further document what some parts of a scenario are doing.

Scenario

The entire contents of the scenario is contained within the Scenario tag:

<Scenario app="Post T Amsterdam CS" description="MyScenario" startDate="1965-10-30" startTime="08:10:15">

<!-- Scenario contents go here -->

</Scenario>

The scenario tag has three mandatory attributes:

• description: The name of the scenario. This is not localised on purpose, as everyone should refer to a scenario using the same name.
• startDate: The date that at which the scenario begins. Times used in this scenario are relative to this date. The format of the date is always the same: YYYY‐MM‐DD, where January 1st, 1965 is represented as 1965‐01‐01.
• startTime: This is the time at which the scenario begins. The format of the time is always the same: HH:MM:SS, where HH is 24-hour time. If the scenario is to start at 9:53:25 PM, then the time is represented as 21:53:25.