S5 S flags?

geniusintraining · Jun 17, 2006

I did not want to hijack Paul's thread... I have several S5135's some 928's and some 943's CPU's, but the programmer did not use any S flag's, are they any different than the F flag's.

Simon referred to them and said that they would work in a 928, so just for kicks I put one in a 943 and it appears to be working

Would the difference be just be for description purposes?

Thanks,

SimonGoldsworthy · Jun 17, 2006

They are just another storage area. I think you can only refer to them in FB's so they are not quite interchangeable with F flags.

geniusintraining · Jun 17, 2006

Thanks

PLucas · Jun 18, 2006

SimonGoldsworthy said:
I think you can only refer to them in FB's so they are not quite interchangeable with F flags.

Not so sure that is true Simon,

As I mentioned in the other thread that Mark linked to, we do use S flags and I am pretty sure that they are referenced and set within PB's and they behave in the same way as F flags.

We mainly use them to 'interact' between the DB that holds the information from WinCC and the main program, by that I mean the WinCC writes to a DB, the DB bits control the S flags, then the S flags are used within the program as per normal,

Paul

moggie · Jun 18, 2006

The CPU 928B has 8192 S Flags in total.
S 0.0 to S 1023.7

Different CPU's have a different number of S Flags; the CPU 948R range is S 0.0 to S 4095.7.

The S flag can be accesed the same as the F Flag range but cannot be used as actual operands with function bock calls or for IPC flags etc.

Hope this helps

PeterW · Jun 18, 2006

The early S5's, 150u's and 115u's only had F flags, not sure if early 135u's were any different.

When 155u's came out they had bigger memory (150u's were restricted to 48K

), so Siemens created another flag memory area which expanded the flags available, the S flags. They couldn't expand the the original flag area beyond the 256 bytes, can't remember why.

Long time, at least 10 years since I played with S5 but I'm sure S flags could be used anywhere, maybe wrong there though.

CT782 · Jun 18, 2006

We have a program running in a 948 referencing S flags and SY flags. Does anyone know what the SY flags are? Same as S flags?

Thanks

SimonGoldsworthy · Jun 18, 2006

S=F = a bit
SY=FY = a byte
SW=FW = a word etc.

Gup · Jun 19, 2006

The big difference is that S flag's are not remanent like the F flags. S Flags loose their value after a CPU stop or power-down, while F Flags don't (at least not all, depending on CPU type and settings). 'S' comes from the German word 'Schmier' which can be used like 'clipboard'. It's temporary, but not comparable with the L-area from S7.

geniusintraining · Jun 23, 2006

Fyi

FYI...A 'S' flag in a 115u 943 (FB)...Will crash the CPU...Trust me Opps, now when is that undo button???

PeterW · Jun 23, 2006

:nodi: probably, unless its changed in the 10 years since I last programmed a 115u, there are no 'S' flags in 115u's.

The programming package will let you do though as its a standard packege for all S5's, it relies on you knowing what the CPU can and cant do.

geniusintraining · Jun 23, 2006

PeterW said:
it relies on you knowing what the CPU can and cant do.

That was the first problem Peter (it relied on me)

, but what the heck I learned something

S5 S flags?

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