This manual provides descriptions and examples of S7 functions FCs and function blocks FBs in ladder logic (LAD) representation. These FCs and FBs are available to program your S7-300/S7-400 programmable logic controller (PLC). This manual is intended as a reference to provide the necessary information for each function. The FCs and FBs described in this manual are located in the Standard Library of STEP 7. Using your STEP 7 file manager, you can copy the FCs and FBs you need to your destination program directory. First make certain that your program does not contain any FCs or FBs with the same.
