dear sir

how to make fb in program with  tia v13

thanks

Hello,

on the project under the PLC create a new program and select FB.

Regards

Christoph

After you added a CPU you find "Program blocks" in the project tree. Open it. Inside there is "Add new block" A dialog box will open and now you can select OB, FB FC or DB.

ChristophD

Hello,

on the project under the PLC create a new program and select FB.

Regards

Christoph

dear sir

i have no idea about fb. iam asked that what the purpose, we use the fb in program ,why we use it.what the need we have to create it,is that have some memory,or it work like as db

Hi,

FB = FunctionBlock

This is executable Program code which you can call from a OB to execute this piece of code.
The Data of the FB is stored in a instance DB of the FB and can be read after the execution of the FB.

The diference between a FB and a FC is that the FC have no DB for the data so the data can't read after the execution of the FC.

Regards

Christoph

Hello qwery,

FB = function block

FC = function

As already explained by Christoph, both (FB and FC) hold executable code. A FB has an instance DB (instance data block) where all values of the FB will be stored. A FC does not have an instance DB, thus its values can not be stored between calls.

So whenever you need static memory (i.e. values that have to be stored between different calls) you will have to use a FB.

OB = organization block

An OB also holds code without an instance DB and thus is quite similar to a FC. It is used to call FBs and FCs to handle special tasks (like program task). FBs and FCs can be called either permanently or conditioned.

regards