QUESTION:  
How can you effectively remove unused modules (FB, FC, SFC) in the CFC container and/or in the S7 module container in SIMATIC PCS 7 V6.x? 

ANSWER:  
During the configuration and commissioning of a Simatic PCS 7 project, it might happen that modules (function modules, functions or system functions) will be added in a project and afterwards deleted again, because they will not be used again.  

Even after deleting a module in a CFC-plan it will still be maintain in the project database in the folders "Planes" and "Modules" in the component view of the SIMATIC Manager, if it's not used in a further CFC-plan. This no more needed module will be additionally loaded into the PCS 7 AS while saving.

As of SIMATIC PSC 7 V6.x a new function is available which removes in a convenient way modules that are no more needed  . The procedure for the use of the function "Clearing" will be described below:

The following scenario might appear. The module DOSE (FB63) will be placed in a CFC-plan by doing drag and drop. You realize after testing the functions that this module is not needed anymore, and has to be replaced by another module. The DOSE module will be replaced by another module. However, the DOSE module (FB63) will remain offline in the module folder and stays in the plan folder. The new function "Clearing" offers now multiple possibilities to remove the module from the both folders.

1. Open an arbitrary CFC-plan and switch into the menu "Module types" by clicking on "Extras > Module types" . The now opening dialog box displays the modules in the module folder offline and the plan folder - independently on whether the modules are still placed in a CFC-plan or not.

 
 Fig. 1: Opening of the menu module types in the CFC-Editor

2. The button "Clearing" is available (black highlighted), if modules, which are not  present in the CFC-plans of a PCS 7 ASanymore, are available offline in the module folder or in the plan folder modules . The button "Clearing" is not available (dawned), if this is not the case. Activate the "Clearing" button, in order to get to the choice dialog for the deleting of modules.

Fig. 2: Starting of the function "Clearing" in the CFC-Editor

Hint:
The command "Clearing" can only be executed, if modules,which are not placed in a CFC-plan, exist in the plan folder or if they are offline in the module folder .

3. The next window shows all module types which are important but not  available anymore in the CFC-plan. In order to delete them they have to be activated. In this case the modules BSEND, DOSE, CH_DI, CH_DO, CTRL_S, DIG_MON should be removed from the plan folder and from the module folder offline. Press the "OK" key after the selection of the modules.

Fig. 3: Selecting and removing the modules in the plan folder of the project

4. In the following dialog box the same steps have to be executed again for all module folders offline, except for the modules in the CFC-planes. After the modules were deleted from the constituent folder offline, the dialog has to be closed with the "OK button".

Fig. 4: Selecting and removing the modules in the module folder offline.

All modules which are not needed anymore, can be removed from a PCS 7 AS simply and comfortably with the function "Clearing" in SIMATIC PCS 7 V6.x. Thanks to this option the overview increases  and the memory requirements of the CPU are reduced.