Accessing UDTs from WinCC

Hi all,
I am new to Siemens, and it seems like it is not possible to access a Step7 v5.4 UDT instance data from WinCC6.0;
Is this true, and if YES, what can I do to go around this?!
(my application is big; i can't go with non-structured programming)
Many Thanks.
Sinan!

Not sure about UDT

But you can surely access user defined DB's from WinCC !!

Not sure about WinCC

I do know Protool and WinCC Flexible though.
And with those you can symbolically access the DB variables that are defined by means of UDTs.

Hello again,
I found this FAQ (Entry ID:14054155) on the Siemens website:

"
Why can't you transfer the elements of an S7 structure or UDT to WinCC through OS compilation?

Description:
In a data block you have assigned the system attribute "S7_m_c" to variables so that they can be operated and monitored in WinCC after OS compilation. This works with simple variables in the data block, but arrays, structures and UDTs are not transferred to the WinCC data management. As from STEP 7 V5.2 and PCS 7 V6.0 it is no longer possible to assign the system attribute "S7_m_c" for elements of structures, arrays and UDTs.

Explanation:
In data blocks the "OS Compile" function doesn't support any structured data types like ARRAY, STRUCT or UDTs (user-defined data types). WinCC doesn't support any declaration of structures within a structure. A data block is already created in WinCC as a structure - so no more structures can be defined within the data block.
This also applies for the definition of structures in function blocks.
"

Click to expand...

The thing is, I wonder how other engineers manage big projects with WinCC and Step7 without connecting UDTs to WinCC, there must be something I am missing. User defined DB (as suggested by 'manmeetvirdi' above) will not be much of a help (as I understand -please correct me if I am wrong) since you can't make several instances of a DB, and then change the original one while the others follow the change automatically. Also, using just DBs, you don't have a functionality similar to using a user-defined datatype as a part of another bigger one... DBs are not datatypes after all.
Any other techniques?

I am guessing that the FAQ is about a special technique with WinCC where you can onfigure objects in the STEP7 program from WinCC.

Have you actually attempted to access STEP7 symbols, including UDT defined variables in DBs ?
I just made a test with WinCC Flexible and there were no problems.

Hi Jesper,
Yes, i have attepted to access Step7 DB symbols: I can see those of a simple datatype (bool,int,real...) but I can't see those of a user-defined datatype!
I am using WinCC6 SP3, so you think SP4 would solve the problem?! What I got from the FAQ is: WinCC(SP3, SP4 or any SP till now) doesnot support UDTs, but of course I might be misunderstanding it!

Also, note this Siemens FAQ (Entry ID:22016523):

"
Which S7 data types does WinCC support?

Configuration Notes:
WinCC supports the following data types:

Datatype \Format adaptation

Binary variable \No
Signed 8-bit value \Yes
Unsigned 8-bit value \Yes
Signed 16-bit value \Yes
Unsigned 16-bit value \Yes
Signed 32-bit value \Yes
Unsigned 32-bit value \Yes
Floating point number 32-bit IEEE 754 \Yes
Text variable 8-bit font \Yes
Signed 8-bit value \No
Raw data type \No

The following data types of a global S7 data block can be
transferred to WinCC and displayed: BOOL, BYTE, WORD, DWORD,
INT, DINT, REAL, CHAR, STRING

Note:
UDTs (user-defined tags) are not supported.

"

Click to expand...

!!!!!

From that FAQ:

This also applies for the definition of structures in function blocks.

Click to expand...

This is VERY strange methinks.
WinCC has less functionality than WinCC Flexible !

Yes VERY strange; this functionality is critical to the function of WinCC as a high-end SCADA software, and this is what drives me to think that there is sth missing here, this cant be it, right?!! There must be sth I dont know!

Contact Siemens support, or post the same question on Siemens own forum.

Yes, I will (Inshalla);

Many thanks!
Sinan!

Hello Jesper,

FEEDBACK:

It seems that I cant find THE solution for my problem,, but I can create a structure in WinCC identical to the UDT in Step7 and then make a tag of it and give it the starting address of the corresponding tag in the Step7 DB. Now this would seem perfect, but WinCC doesn't support (nesting) structures within structures as Step7 does (which is the cause of the original problem), and so I have to disassemble the 2nd level structures in the first level structures (e.g.: Page1.Line1.letter1 should become Page1.line1_letter1,...etc!!!!).
The other option is to extract 2nd-level structures from 1st-level structures and directly instantiate tags from them with appropriate names (e.g.age1_line1.letter1).
Of course, the choice depends on the application; in my case, the second option takes less time and is more useful.
If the application needs deeper nesting (Library.Book.Page.Line.Letter), this problem will be a nightmare and switching to a better system is a must (I think)!

Sinan!

What I do not understand is why WinCC cannot support this feature whereas WinCC Flexible does.

WinCC shall be migrated to WinCC Flexible in the future. It should have happened by now, but I am not surprised that it has slipped. It will be 2008 or 2009 before it finally happens I guess.

I hope so; You know, I thought -since WinCC is the high end SCADA solution from Siemens- that WinCC flexible is a degraded version of WinCC with less functionality to cut on price to suite HMI applications, but it appears not...
Hearing from you, I will sure investigate Flexible as soon as I have the time!!!!
Regards,
Sinan!

Flexible certainly allows you to (powerfully) define UDT's/structures - the only thing lacking is the inability to link a data source in a structure to a trend variable - so you can make a beautiful PID loop faceplate but not be able to link PV OP and SP tags from the structure into the real time trend .