Hi dear all,

In my project by pcs7 v8.1, i am trying to activate redundancy io for 2 analog input modules that located on 2 et200 modules seperately. 

I have done all requirements for this operation (from the manual: 28430682_Projektierung_red_IO_V81_en) and also tested by plcsim with tow existing selectable options for Value applied: Lower value and higher value. 

At first and after several changes in the analog input channels all thing was ok and i could see the normal operation of redundancy io without any problem. But in continue and after more changes applied on analog input channels, the redundancy io operation was corrupt and 2 analog input channels had their input value without any effect on each other in the redundancy form.  

At finally i could solve my problem by restart of the plcsim. But i can not use that solution on a real PLC in a runing plant; because the problem is repeated more times. 

Any solution please.

Best regards

Tekabi

Hello Tekabi;

You are testing your redundant I/O program with PLCSIM?

You might find this dscussion very interesting, pay special attention to Phantom_75's last post, where it is stated that:

"you cannot test I/O redundancy using PLCSIM. The reason for this is, some of the system function blockscannot be processed "normally" by PLCSIM. See the following FAQ:

What is the difference between S7-PLCSIM and a "real" automation system?"

You misght have to wait until you hace actual hardware to do the FC 450 tests.

Hope this helps,

Daniel Chartier

Hi dchartier, 

Thanks for your reply.

Yes, i am testing by plcsim now.

And the red blocks are automatically created  in the system chart. Additionally do i need to add them manually again?

Regards

Tekabi

Hi,

No need add them manually, Chart folder download is sufficient for system generated charts and blocks.