UDT in declaration S7

Thim · May 14, 2009

Hello folks,

Had a question about S7
I the declaration of a FB i add a UDT
The UDT excist out of a struct
The struct has different variables in it
Now i want to know the adress area of this variables.
Assume that UDT name is A Struct name is B and variable is C then i can load this value by typing

L A.B.C

Normally when i want to know the adressarea i would type

L P##A.B.C

But this doesn't seem to work, someone out there who can help me out with this?

Thx

PeterW · May 14, 2009

que?

Do you mean a UDT which contains a STRUCT and you want a variable from within that struct ??

sylent · May 14, 2009

Put the UDT declaration in the IN_OUT area and call it PUMP1
to pass the UDT into the FB it would be
A.B.C (where A is the name of the DB where the struct resides B is the STRUCT name and C is the name of the declared UDT) and D would be a variable in the UDT

But inside the FB to use the variables from the passed UDT it would be
L #PUMP1.D

Thim · May 14, 2009

Yes i want the adress area of that variable not the value of that variable
I will add a picture from what i want

Thim · May 14, 2009

I Want to determine the adress area 58.0

PeterW · May 14, 2009

What I have done in the past is create a TEMP of the same UDT, then the FB input as a pointer.

Using SFC20 I passed the data into the TEMP area, then use the TEMP area as normal access to UDT's.

At the end if required pass the updated data back in the reverse of the above.

PeterW · May 14, 2009

If you just want to pass one item in, you can do that alone, ensure your are addressing symbolically.

PeterW · May 14, 2009

Thim said:
Yes i want the adress area of that variable not the value of that variable
I will add a picture from what i want

Sorry just read this bit

as above with a pointer and create an ANY, offsetting the start address and length to the variable you want.

IN: UDT_POINTER

in the block

L P##UDT_POINTER, which gets you to the start of the UDT.

Thim · May 14, 2009

Yep that is correct what you say i can determine the Start adress of the UDT.
But if you mean IN:UDT_pointer you mean i have to write P#58.0??
So i have to know it correct ? Or do i understand this wrong
Is there a way that Step7 determines it by it self by adressing it symbolically
If i change the UDT the adress would change also automaticly, or isn't this possible

Thim · May 14, 2009

I use this UDT also somewhere else in an array.
Now i code directly

L 58
SLD 3
LAR1
....

If i would ever change this UDT i have to go through the whole code to check everything so i was just checking if there would be a way to determine it

PeterW · May 14, 2009

No not p#58.0

If your DB is called "DB" and the UDT is withinn the DB called 'UDT10', then at the FB call, put in "DB".UDT10 (NOTE, as I said you have to be in symbolic addressing mode).

In the code you would need a TEMP set up as an ANY and you can then use the pointer inputted as material to build the ANY.

That will be pointing to the start address, so you would then need to offset your start address to the word you want.

PeterW · May 14, 2009

The TEMP UDT maybe the best solution, if you push it into the TEMP area, if you change the UDT you would need to update the TEMP area, but the code would still be OK if its accessing the data symbolically.

Thim · May 14, 2009

I will give it a try and see what happens.

Thx allready

L D[AR2P#0.0] · May 15, 2009

Use the following FC to achieve the functionality of

L P#A.B.C

If you don't need the DB, remove it from the FC interface.

Code:

FUNCTION FC 2 : VOID
TITLE =
VERSION : 0.1

VAR_INPUT
  pData : POINTER ; 
END_VAR
VAR_OUTPUT
  dwArea : DWORD ; 
  iDB : INT ; 
END_VAR
BEGIN
NETWORK
TITLE =
      L     P##pData; 
      LAR1  ; 
      L     W [AR1,P#0.0]; 
      T     #iDB; 
      L     D [AR1,P#2.0]; 
      T     #dwArea; 
      SET   ; 
      SAVE  ; 
END_FUNCTION

Example call in use:

Thim · May 15, 2009

thx LD

UDT in declaration S7

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