Dear all,

Normally I don't use SFC (sequential flow chart) in my projects, but this time, the nature of the problem seems to be expressible this way in the most elegant manner.

Briefly, it's about controlling a complex hydraulic system, to run sequential programs via manipulating valves and pumps. There are basic sequences like:
Backwash DF :
- Make sure pumps are off
- Set valves on DF
- Start pumps
- Make sure flow and pressure is established
- Wait 30s or 0.4m3
- Stop pumps
- Reset valves to normal position

There are a dozen of such "action groups", what would be nice to be used in higher level programs, like
- * Production * (backwash before starting)
- * Shutdown / standby * (backwash regularly)
- * CEB / CIP * (backwash as needed)

Naturally, I can write to whole thing using ST, and a state variable, or SFC, with long sequences, but I was wondering, if it's possible to define "reusable" macros in SFC to do this. I know it's possible to define macros in SFC, but they doesn't seems to be reusable in other parts of the structure.

What is the standard way to reuse one SFC program, with standard INIT - EXIT from within another?

Thanks for any recommendations,

P.Peter