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Names and Naming Rules

This chapter covers the encoding of object names and folder names, as well as the applicable naming rules, and the folders reserved for CODESYS File-Based Storage.

Encoding of names

Object names and folder names sometimes contain characters which are not permitted in file system paths or which have a special meaning. These characters are encoded by CODESYS File-Based Storage so that the project remains portable between Windows and Linux.

The following characters are encoded:

  • Characters which Windows does not allow in a path: < > : " / \ | ? *

  • Caret (^) because since it identifies container directories

  • All control characters

  • Period (.) because it separates the name from the class part and language part

Each encoded character is written as two underscores followed by the two-digit hexadecimal code of the character. Thus the point becomes __2e, the slash becomes __2f, and the caret becomes __5e.

If an object name matches a reserved Windows device name, then the name is enclosed in underscores. Reserved Windows device names are CON, PRN, AUX, NUL, COM1 to COM9, and LPT1 to LPT9. CON will become _CON_.

Naming rules

To make sure that projects remain portable and suitable for version control systems, CODESYS File-Based Storage will check the object names. Violations are reported.

  • The object name, including the class suffix and the language suffix, must not exceed 240 characters. A folder name must also not exceed 240 characters.

  • Object names must not contain a hash symbol (#).

  • Object names must not begin or end with a space character.

  • Two folders cannot have the same name, even in different parts of the project. The comparison does not take case sensitivity into account.

  • A programming object must not contain two methods with the same name.

  • A project must not reference two libraries using the same namespace.

If CODESYS detects a violation during a conversion, then the problem will be reported. If possible, a quick fix will be provided. The Convert Project command describes the available quick fixes.

Reserved folders

Several folders are used by CODESYS File-Based Storage for internal purposes, including .FBS_Project_Related, .auxiliaries, and .sidecars. Do not create project folders with these names.

The .auxiliaries and .sidecars folders include local or generated contents. Always exclude these folders from version control systems.

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