S7 300 CPU314C-2 DP SF and BF red ligths

Hi everyone!

I'm working with a S7-300 314C-2 DP and the SF and BF lights is on and i cannot communicate with PLC. This problem starts when I download to device a simple function block. After that the only option to communicate is PCLSIM.

In Online Diagnostics show me this message:

Differences were found between the loaded configuration and the offline project.
Online order number:  6ES7 841-0CC05-0YA5
Offline order number:  6ES7 314-6CH04-0AB0
This difference is accepted by the system because the inserted module is compatible with the loaded module.
Module exists.
OK

Before I download the function block, doesn't show this message!

One more thing: The CPU is always in STOP mode, when I try to put in RUN mode, show me this message:

"The action cannot be performed with the current mode keyswitch setting on the module."

I'm using TIA Portal v13.

How can I solve this!? That's makes me crazy! Someone can help me? :)

Thank very much!

Sorry about my english :(

Leonardo" Vardiero

Hello Leo.dmly,

according to your description I assume following:

you have changed a specific function block, not only in network area, but also in data area. Maybe you have added/deleted/edited variables in static, in or out section. Then you have saved all changes in the FB and downloaded only this FB.

If so you have to be aware, that changes in data area of an FB will require to adapt all other functions referring to your changed function. This applies to all calls of that function, as additional/less variables have to be serviced at call.

Thus if you changed data area of a FB and downloaded only the changed FB, all calling functions will be invalid and this leads to SF and CPU STOP.

To solve the problem you have to open all OB/FB/FC that will call your modified function and search for the networks where the function is called. Its likely that you will find your function there marked in red. Click on it (I am not sure if double click or right click) and system will offer you to change call to new FB. After accepting the called FB in that network should be black again. Store that function and mark it for later download.

Proceed like that with all functions calling your changed function. You can use cross reference to find all functions referring to your function.

After changing all referring functions, download all marked referring functions and your modified function at once. The problem should then be gone.

regards

eisenpferdreiter, thank you very very very much! I did it and works =D