This documentation describes the package Snap7, what it consists of and how to use it.

It’s written in Internet English, a kind of English with many syntax errors and a very questionable style.

The hope is that the message, though with much “syntax noise”, it is understandable to all.

And, if the Internet English was not enough, I’m neither a writer nor a publishing expert, so, please, do not expect to read an award winner book.

You are warmly encouraged to send comments/corrections.

Rarely I read a manual from the beginning to the end, and I think that many other people do the same, so, many key concepts (such as PDU) are repeated throughout the entire manual to allow a “spot” consultation without the loss of information.

The reference manual that you find in the package, in addition contains the complete API syntax and error codes.

Convention

· Every concept or code snippet applies both for 32 and 64 bit architecture (including LabVIEW and plain C compilers).

· Unless otherwise specified (rebuild), Unix stands for Linux or BSD or Solaris.

· Unless otherwise specified, every concept or code snippet applies both for Unix and Windows regardless of the source code wrapper (C/C++/C#/Pascal), they were tested under all the platforms deployed.

· There is no special chapter about small ARM Linux boards (like Raspberry) because Snap7 offers the same functionality for these boards.