Mitsubishi Electric MELSEC iQ-F Series Quick Start Manual page 56

3.
Select the "StrProcessing_F.mslm" file in the decompressed FB library folder, and click [Open].
4.
The selected file is added to [Library] in the "Element Selection" window.
If the "Element Selection" window is not displayed, select [View] on the toolbar  [Docking Window] 
[Element Selection] to open the window.
APPX
55
Appendix 2 FB Library