frequency drive profibus communication

i have keb f5 frequency drive profibus comunication with s7 300

if one of my drive fails(fault on drive) my machine stops

so i want to bypass my frequency drive program ( the faulty one so rest of machine works ) in step 7 because these is no option on HMI

i know step 7 reads slave data through SFC14  but i can't manage it

so kindly help me with this issue

i upload the program

Hello Usman;

Very sorry, I do nto have access to Step 7 Classic these days, so I cannot open your project.

In any program developped on a S7-300 CPU that would include Profibus connections, I would make sure that (at least) the diagnostic OB OB86  (I/O Rack Failure) is included in the project; I would generally have also OB122 (I/O access error) in the CPU memory.

Are you familiar with diagnostic OBs? These are blocks that are called by the Operating System of the CPU (not the program) when certain errors are detected in runtime; as their name suggests, OB 86 is called when the CPU loses communication with a remote I/O rack, as is happening with your drive. OB 122  would be activated when your program triess to access addresses that were linked to the failed remote I/O rack in question.

Once activated, the diagnostic OBs do 2 things automatically: they gather data that will help locate the source of the error, and post them in the diagnostic buffer nessages; and they will not let the CPU go to STOP mode when this type of  error happens. The CPU will remain active, with some active LEDs (SF, BF) so you can see there is a fault, the détails of which you can see in the diagnostic buffer. Open the diagnostic buller with CTRL+D in Simatic Manager.

Open you project's Blocks folder and see if these diagnostic OBs are part of your program. If they are not available, create them (in the Blocks folder); with a right-click, select New Block, type OB, and name it "86". Once created (no program necessary at this time), save, compile anbd download to your PLC.

The next time your CPU encounters the same error, diagnostic LEDs will be active, and you CPU will un. Open the diagnostic buffer to find out what error messages have been logged.

If you need help to understand the messages (it takes a bit of practice to get used to them), you can save the diagnostic buffer messages (there is a button don the diagnostic buffer page to do just that) and post the error log here as an attachment. We might be able to help,.

Hope this helps,

Daniel Chartier

 Hello,

usman aqeel

 i want to bypass my frequency drive program ( the faulty one so rest of machine works ) in step 7 

 Perhaps the following topic might help:

Taking off drives from profibus