Siemens S7 - begin address of FC or FB code

[darekk0000]

Hi all,

I need find begin address of code for FC or FB function. Do you know how can I find this?

Next I need copy part of FC or FB code to DB. It should be easy I suppose (using lar1 or pointer).

Best Regards,
Darek

 

[JesperMP]

Wha.. ????

Try to explain exactly what you want to achieve.

 

[darekk0000]

Just I need machine code for S7.
I have found machine code for S5 but I can not find this for S7 and my idea is get it from PLC.
To be sure machine code for S5 e.g.

0x8000 - A M x.y​

0x8800 - O M x.y​

:​

0xB000 - R M x.y​

etc​

I need exactly machine code for logical operations for S7 PLC.​

​

​

​

 

[JesperMP]

There is no way to do this from the S7 program.

I have heard that the LIBNODAVE comms library allows to upload and download code blocks. Maybe you can use that as a start.

 

[darekk0000]

It is for sure possible. I remember a few yers ago I have wrote program which changed NOP 0 instruction to BE and oposite in real time. But I can not find it now.
I remember i used one of SFC function to do this, but which ... I do not remember.

 

[PeterW]

Wha.. ????

Try to explain exactly what you want to achieve.

I repeat that question??

As far as I know you cannot auto gen FC's and FB's from within the code and if your planning on altering status words to point to areas within DB's, I would have thought that would be dangerous.

As far as the machine code's concerned,I know in S5 it was listed in the instruction manual but I have never seen it in S7 manuals.

 

[darekk0000]

answer as above

 

[L D[AR2P#0.0]]

Darek - just to clarify, you have written some self modifying code in Step 7 ? (As has been said, it is possible with Step 5).

 

[darekk0000]

exactly, but it was a long time ago.

BTW
b#16#18 - it is FC area tag

Best regards,
Darek

 

[S7Guy]

I was also under the impression that the M7 code was not accessible with S7. Are you sure you didn't do this with one of the M7 processors? Or with the 614 CPU that uses assembly code?

 

[darekk0000]

I am sure it was after I had changed S5 to S7 (s7-315). I did not know then that it is impossible.
PeterW - I am aware that writting self modify program is dangerous, but I need this for decoding machine code coming from CPU and display it in dialog window.
regards,

 

[PeterW]

Sounds an interesting project