Basic Architecture
The Safety Editor can be logically divided up into three levels. The basic level is the already known I/O structure within the TwinCAT system. The I/O structure is used to configure the complete system (non-safety and safety components) on field bus level. The highest level is the safety editor, which consists of graphical interfaces to deal with the programming of the safety-relevant application. The third level constitutes the connection between the application level and hardware level. Within this level, all safety-relevant information is administrated and stored (for example the parameters for input and output terminals). The schematic architecture of this 3-level system is shown in the following Figure:
The lower level (Hardware level) can be found within the I/O-Subtree of TwinCAT 3. The upper two levels can be found beneath the Safety node of TwinCAT 3.
To view the upper two levels, a new safety project has to be created.