Hi Late,
I try to be more clear [:blush:]..
I just "write" the output fields of the S7 slave and read the input fields of the S5 master...
In the S7-400 configuration, I reserved an output fieldthat starts at the addres A 110,and has a lenght of24 bytes for the profibus comunication, and I reserved also an input field that starts from the addres E 130 with the same lenght.
In theCOM Ncm Idid the same thing, crossing the addresses( the slave inputs to the master output and viceversa)..
Now in theS7 program i simply write this line :
L 10
T AB 110

L 11
t AB 111

...etc, using all the 24 bytes..

In the S5 program I read those bytes just reading the input addresses..
LPY 110
T MB 10

L PY 111
T MB 11

etc..

When I try to read the MB , I see the values written by the slave, but they are not "fixed"..They dance!!?! ..
It all starts from the Fifht byte..the first four are ok but from the others change their value in a crazy way..
I hope now its more clear..

Hi Victor,

I have looked to your project and couldn't find errors, the only thing i found was in the STEP5 program that you are using PY, because it is in the PPI that is maybe wrong.

So change it in L EB .... [;)]

FB 1
Netzwerk 1
:L EB 110
:T AB 4
:
:L EB 111
:T AB 5
:
:L EB 112
:T AB 6
:
:L EB 113
:T AB 7
:
:L EB 114
:T MB 8
:
:L EB 115
:T MB 9
:
:L EB 116
:T MB 10

Are there no other cards placed in the same IO-adresses space in the rack or in a expansion rack of the S5?

I didn't see outputbytes that are going back to the S7...

The adresses are by unit, so thats not the problem...

You have taken the timing of the CP5431 to the S7....

Do you change the "ZYKLUSSYNCHRON"once to "FREILAUFEND" ?

CP Typ: CP5431 (EN
(E/A) Bereiche : Quelle: C:Q_DIMUZ1
─────────────────────────────────────────────────────────────────────────────

L2 - Teilnehmeradresse : 1
GP-Aktualisierung : FREILAUFEND
DP-Aktualisierung : ZYKLUSSYNCHRON

Stationen, von denen globale Peripherie erwartet wird:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
X X X X X X X X X X X X X X X
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
X X X X X X X X X X X X X X X X

EINGANGSBEREICHE:

ZI/DP-ANF: PB 110 GP-ANF: GP-END: ZI/DP-END: PB 141

AUSGANGSBEREICHE:

ZI/DP-ANF: PB 130 GP-ANF: GP-END: ZI/DP-END: PB 161

I think that Address 2 is NOT a GP Station, maybe thatgive some strange behaviour... [:P]

The outputs are out of the PIQ so that addresses have to be with T PY....
I didn't find any output addresses in the Program.... [:(]

With the CPU928 it might be so that the addresses have to be read/written in a particular following, but i think not.

So in total i have found four points where you might change something:
- the I/O in the STEP5 program;
- check if there is not I/O in the rack or expansion rack(s) with the same addresses as the 5th byte;
- the 'X' under the 2 of GP addresses;
- Try the "ZYKLUSSYNCHRON"to change in "FREILAUFEND", i haven't the book of the CP5431 here to check what the difference is;

Good luck, this was why i say directly in the beginning change it to the IM308C, then it have worked now for a long time.... [:)]