How do you read a syntax diagram?

How do you read a syntax diagram?

How to read syntax diagrams

1. Read the syntax diagrams from left to right, from top to bottom, following the path of the line.
2. Required items appear on the horizontal line (the main path).
3. Optional items appear below the main path.
4. If you can choose from two or more items, they appear vertically, in a stack.

How do you read a railroad diagram?

Each railroad diagram begins with a double right arrow and ends with a right and left arrow pair. Lines that begin with a single right arrow are continuation lines. You read a railroad diagram from left to right and from top to bottom, following the direction of the arrows.

What is a train diagram?

Train schedule diagram is a kind of a chart in which information of operational schedules of railway is illustrated. Train schedule diagrams (diagrams, in short) are by far the most important charts in railway operation because various kinds of and huge amount of information is stored in a very compact manner.

What is a railway diagram?

What is a weekly operating notice?

The Weekly Operating Notice (WON) provides information of Safety Notices, Temporary Speed Restrictions, Engineering Arrangements, Signalling & permanent Way alterations and General Instructions & notices for specific regions.

How do Railfans know when a train is coming?

Railroads use what we call line-of-sight communications which means a scanner listener will hear the train crew when they are anywhere from 5 to 10 miles away. Line-of-sight reception is based on the radio transmit power.

Read the syntax diagrams from left to right, from top to bottom, following the path of the line. Required items appear on the horizontal line (the main path). Optional items appear below the main path. If an optional item appears above the main path, that item has no effect on the execution of the statement and is used only for readability.

What is the difference between syntax diagram and syntax fragment?

Sometimes a diagram must be split into fragments. The syntax fragment is shown separately from the main syntax diagram, but the contents of the fragment should be read as if they are on the main path of the diagram.

How do I read a syntax fragment?

The syntax fragment is shown separately from the main syntax diagram, but the contents of the fragment should be read as if they are on the main path of the diagram. For some references in syntax diagrams, you must follow any rules described in the description for that diagram, and also rules that are described in other syntax diagrams.