Step7 V11 using plc data types in FB call

[mattiasLindhSw]

In older step7 versions it was not preferable using direct acess to UDT data in the block interface. (defined as in/out paramters to FB/FC blocks. As we all know doning this would create loads of over head code in the background, making your project grow rapidly.

What about step7 V11, is the code comiled in a smarter way, making it possible to use own defined data types (PLC data types) as in/out parameters to FB/FC block. Or is the limitation the S7 CPU itself.

What about S71200.

Anybody that have done any tests?

 

[mattiasLindhSw]

I made some tests:

The complied blocks is equally big when using tia portal step7 V11 or step7 V5.5. But if using S7 1200 the work memory consumed is much less.

The test used 1 UDT with 32 bool as IN/Out parameter to a FC/FB
All 32 bools were used once within the FC/FB.
See below table:

With UDT
Step7 Version CPU Loadmem Workmem Blocktype Operators
-------------------------------------------------------------------
V11 + SP1 S7315 1720 1574 FC 32
V11 + SP1 S7315 1596 1382 FB 32
V11 + SP1 S71200 5095 132 FC 32
V11 + SP1 S71200 5310 132 FB 32
V5.5 S7315 * 1574 FC 32
V5.5 S7315 * 1382 FB 32

Same code when using 32 separatet bool as in/outs.

Without UDT
Step7 Version CPU Loadmem Workmem Blocktype Operators
---------------------------------------------------------
V11 + SP1 S7315 312 166 FC 32
V11 + SP1 S71200 4518 101 FC 32

Conclusion:
So there is no inprovement in using UDT as inOUt to FC FB for S7300.
BUt there is a big improvement when using s71200

 

[TurpoUrpo]

How could there be? Think about hw arch, u cant just change it on the fly how cpu handles addresses.

s7-1200 is all new arch so they could make it more efficient from the start.