As the name implies, SFC is well-suited for sequential step processes. You will also find that SFC is popular within batch processes as it closely aligns with the step-by-step requirements of batching. It is particularly useful when paired with other IEC languages. Within SFC routines, you use structured text for any logical expressions, assignments, or other constructs. By using the structured text function—JSR—(or similar functions), you can reference ladder logic, Function Block, structured text, or even other SFC routines. SFC can be used as a high-level program flow controller (business logic), and the detailed step logic can be created in separate routines. Structuring a program in this way will make it easy to follow, troubleshoot, and modify in the future.
Now that we understand when it is best to use SFC programming, we will discuss the SFC editing environment in the next section.
