A Controller Application File (CAF) is a file which contains all the logic components needed to represent a system. The tool prompts you to save a controller application file for each system you create. Saving this file allows you to access it again later to make changes or to use it for additional systems.
The default location to save a CAF is C:\Users\<username>
You cannot use certain characters when saving a CAF. Invalid characters include:
: * ? " < > | / \