ST Style guide - References - SIMATIC AX - Support documentation - ST Style Guide, Cheat sheet

Programming guidelines are used to obtain a standard/uniform code that can be more easily serviced and re-used. Not only this, errors (bugs) can be identified at an early stage (e.g. by the compiler) and avoided. The source code should have the following properties:

• A standard and unified style
• Should be able to be easily read and understood
• A certain appearance should initially be maintained regarding serviceability and transparency of the source code. Optical effects – e.g. a standard number of blanks before the comma – only play an insignificant role regarding the software quality. It is far more important for example, to find and select rules that support development engineers in the following way:
• Avoid typing errors and careless mistakes that the compiler then incorrectly interprets. Objective: The compiler identifies as many errors as possible.
• Support the code for identifying and resolving program errors and bugs; Objective: The code indicates problems at an early stage.
• Standardize standard applications and libraries Objective: The program code is more easily learned and the reusability of program code is increased
• Modularization
  • Objective: Increasing the level of transparency
  • Selectively use of sub-functions and simple combination of different modules by encapsulating and clearly separating sub-functions
  • Define clear and unique interfaces
• Increase the serviceability and ongoing development Objective: Changes to the program code in the individual modules, that can involve functions/function blocks/programs or units in libraries or in the projects – should have a minimum impact on the total application/total library. Different programming engineers should be able to make changes to program code in the individual modules.