Diagnosing Hardware and Troubleshooting Siemens S7 PLC

How to Locate Faults

1. Open the online window for the project with the menu command View >
Online.
2. Open all the stations so that the programmable modules configured in them
are visible.
3. Check to see which CPU is displaying a diagnostics symbol indicating an error
or fault. You can open the help page with an explanation of the diagnostics
symbols using the F1 key.
4. Select the station that you want to examine.
5. Select the menu command PLC > Diagnostics/Settings > Module
Information to display the module information for the CPU in this station.
6. Select the menu command PLC > Diagnostics/Settings > Diagnose
Hardware to display the "quick view" with the CPU and the failed modules in
this station. The display of the quick view is set as default (menu command
Option > Customize, "View" tab).
7. Select a faulty module in the quick view.
8. Click the "Module Information" button to obtain the information on this module.
9. Click the "Open Station Online" button in the quick view to display the
diagnostic view. The diagnostic view contains all the modules in the station in
their slot order.
10. Double-click a module in the diagnostic view in order to display its module
information. In this way, you can also obtain information for those modules that
are not faulty and therefore not displayed in the quick view.
You do not necessarily have to carry out all of the steps; you can stop as soon as
you have obtained the diagnostic information you require.