Siemens s7 buffer showing OB121 error

I am facing a plc system fault on plc.when I checked the ddiagnoss buffer it shows
Area length error when writing
Access a dress 432
fc number 83
Module adress 46

Any one suggest how to identify the faulty device.

Open FC83 with the LAD/FBD/STL editor.
From the menu Edit .. Go To .. Block Address.
Specify 46 at the popup that appears.
The cursor will then be at the offending address.