Dear friend Kal.A.... careful with you answer.

Kal.A

Upgrading V3.x to 4.x is not possible.

It is depending what was asked by the question -
(a) Updating firmware in the physical PLC from FW3 to FW4
- OR -
(b) Taking a project that has been developed for FW3.x and change the software to work for FW4.0 or FW4.1

In case of (a) - - - totally correct.
In case of (b) - - - this is possible.

Dear Zvonko1952,

Zvonko1952

Does anybody have ( positive) experience in upgrading CPU 1214C V3.0 to V4.0?

I have upgraded with success a software program developed for FW3.0 to be able to work on FW4.1. What made it tricky is that there were HSC and Motion Control that required upgrading too.

Please come back and explain in more detail what your problems are and let us see if our community can help you through it. Screen captures and explanation of the symptoms / error messages will be most helpful to us.

Hear from you again (?)
w

You right click on the plc in the device view, select change device, and select the 3.0 firmware version.

Compile hardware.  Download hardware to PLC.  Check for all green lights on all hardware and no new blinky lights. (This is a sanity check).

Compile/rebuild all software.  If you have communications other than HMI and profinet/profibus, you may need to adjust the instruction block version level down one (or more).  This may require you re enter some interface tags to pick up the version changes to the data types hidden within.

Once you get successful compile, download and start.  Should be pretty close to working right there. 

Zvonko1952

Thank you all! It seems that my interpretation of entry ID 67190848 and attempt to utilize files from Entry ID 107539750 were incorrect! Nevertheless, let me make a comment on CristopherD's suggestion, because, out of pure  despair, I have already downgraded project from V4.0 to V3.0 ,which I was hesitant to implement yet for several reasons and they are all customer related and therefore beyond this post.There were two issues with this solution:

a)  you are going to lose the program, completely; I overcome this problem by copying blocks to Project Library BEFORE the PLC switch! If you know of more elegant solution please let me know.

b) You (might) loose some compatibility with existing project components, in my case, HMI!

Regards,

Zvonko