You do not need a sketchy RAR file. Here are the official ways to get the current manual:

In the intricate world of model railroading, the landscape is defined by two types of enthusiasts: those who simply watch the trains go round, and those who obsess over the digital nervous system that powers them. For the latter, few documents hold as much mystique and practical necessity as the "Signalbuch"—the signal book.

The is an outdated, risky way to seek documentation. Viessmann offers the same content legally, safely, and for free as a direct PDF. Protect your computer and your model railway investment by downloading only from viessmann-modell.de or authorized resellers.