Siemens s7-300 declaration problem

Hi Guys,

I have a problem with a third party piece of software, the declarations from a called FB within my ladder update but wont save and then they give me an error.

The FB100 called is a timer but its been password protected by the author (not sure if this makes a difference) the FB is being called locally but errors on compilation.
I have attached a screenshot with the error shown at the bottom, thanks for your help in advance.

Create a library, insert an S7 progam into the library and then copy the blocks from your project to the library blocks folder. Archive the library and then post it here.

Hi L d[AR",P#0.0]

I have attached the project file this includes all i have.

thanks

Hi DeepThought

Think you need to re-generate the instance data block for FB3 (DB9).

If you open OB1 and go to network 3 DB9 is in red. If you click on DB9 it should as you generate the instance data block, click yes. Then reload the blocks to the PLC.


Jon

Oh if you then run a block consistency check you should find no fault shown in the header for FB 3


Jon

This still does not remove the problem. By the way instance block for FB3 is DB3. After compiling program again the problem remains. There has to be something inside FB100 that prevents it from being used as multiple instance!?

If you cut STAT16 from FB3's STAT declaration table and paste it back in, you can save FB3 with no errors and then open OB1 and regenerate DB3

However, if you open FB3 again, the error re-appears....

Open/Save FB100 resolves the problem.

LD is right. Tha same problem occured to me in the past. This should be a bug of SIMATIC. Just try not to change FB3 much.

educated guess as follows:

FB100 in the original (faulty) project does not have the names of the interface variables stored in the project - this is because it has been uploaded from a plc and FB100 did not exist in the offline project.

The interface variable types are stored though. When you open and save a block with the editor, the editor examines the interface variable types and assigns them names (IN0 etc.) if they do not exist.

As FB100 was a locked block, the editor could not be used to assign names to the interface variables.

When FB3 is opened, then when the editor encounters the first occurrence of FB100 it cannot find any names to associate with the interface variables and the error is reported.

Subsequent references to FB100 use the interface variable types for FB100 stored in FB3

Solution: Third party to provide FB100 from the original project

Hi Guys
Thanks for your help I thought it could be the FB100 but with it being locked i could not prove it or explain it your help is always appreciated. Have a good weekend one and all.

Should anyone need to fix this type of problem in the future, one method is as follows:

You will need access to a plc or PLCSIM. Ensure FB100 has been loaded into the plc.

Create a library with a S7 program in it and copy FB100 to the blocks folder of the library.

Delete FB100 from the offline folder of the project.

The interface of FB100 is stored in SUBBLK.DBT, and consists of a pair of bytes for each interface variable detailing the data type (01=Bool, 02=Byte 03=char etc) and the interface type (01=IN, 02=OUT 03=INOUT 04=STAT 05=TEMP). If there is a SFB/FB declared in the STAT area, the interface contains the block number and then show the interface of the relevant SFB/FB. With reference to the coding scheme you can search the DBT file to find the relevant hex codes show below:

..continued

Here is the interface de-coded

Once you know the interface, create a new FB100 in the original project (the one you have deleted FB100 from) with an interface as determined above. No code is required in this FB100.

Finally, copy FB100 from the online folder (the plc or PLCSIM) to the offline folder. FB100 will now have a named interface and the original locked processing logic.

L D...