Function Block Diagram (Fbd); Scl - Siemens SIMATIC S7 System Manual

Consider the following rules when creating a LAD network:
● You cannot create a branch that could result in a power flow in the reverse direction.
● You cannot create a branch that would cause a short circuit.
6.5.2

Function Block Diagram (FBD)

Like LAD, FBD is also a graphical programming language. The representation of the logic is
based on the graphical logic symbols used in Boolean algebra.
Mathematical functions and other complex functions can be represented directly in
conjunction with the logic boxes.
STEP 7 does not limit the number of instructions (rows and columns) in an FBD network.
6.5.3

SCL

Structured Control Language (SCL) is a high-level, PASCAL-based programming language
for the SIMATIC S7 CPUs. SCL supports the block structure of STEP 7 (Page 138). You can
also include program blocks written in SCL with program blocks written in LAD and FBD.
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
99BProgramming concepts
6.5 Programming language
To create the logic for complex operations,
insert parallel branches between the boxes.
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