Diagnosis Directly at the PLC by means of “ERR” \ LED, Keypad and Display¶
Note
Diagnosis of AC500 PM55x and PM56x can only be shown by LED ERR at CPU.
If the PLC contains a non-acknowledged error, the red error LED “ERR” lights up.
Note
The CPU parameter “Error LED” in the PLC configuration allows to set for which error class the LED indicates an error. The default setting is “On”, i.e., errors of all error classes are indicated. If the parameter is set for example to “Off_by_E3”, the LED “ERR” does not light up in case of errors of the classes E3 and E4. However, if an E2 error occurs, the LED always lights up.
If one or several non-acknowledged errors exist, the errors can be displayed and acknowledged using the <DIAG> key. The latest non-acknowleged error is displayed first (LIFO-principle: last in first out). Pressing the <DIAG> key the first time displays the error class and error identifier. After this, pressing the <DIAG> key several times browses through the detail information d1=component, d2=device, d3=module and d4=channel. If the “d4” information is displayed and the <DIAG> key is pressed once more, the error class/error identifier is re-displayed.
If you quit the diagnostic display by pressing <ESC>, the error is not acknowledged and displayed again when pressing the <DIAG> key.
If you quit the diagnostic display with the <OK> key, the error is acknowledged.
The LED “ERR” goes off when all errors are acknowledged.
Example:
The error “Battery empty or not installed” appears in the PLC display as follows:
| Pushbutton | Display | Meaning |
|---|---|---|
| <DIAG> | E4 008 | E4=Warning / Identifier = Empty/Not available |
| <DIAG> | d1 009 | Detail information d1 = 009 -> Component=CPU |
| <DIAG> | d2 022 | Detail information d2 = 022 -> Device=Battery |
| <DIAG> | d3 031 | Detail information d3 = 031 -> Module=no specification |
| <DIAG> | d4 031 | Detail information d4 = 031 -> Channel=no specification |
| <DIAG> | E4 008 | E4=FK4 / Identifier = Empty/Not available |
| <ESC> | run/StoP | Diagnostic display is quit without error acknowledgement. |
| <DIAG> | E4 008 | E4=FK4 / Identifier = Empty/Not available |
| <OK> | run/StoP | Diagnostic display is quit with error acknowledgement. If no further non-acknowledged errors exist, the LED “ERR” goes off. |
For a description of the error numbers refer to the chapter Organization of the error numbers The \ Diagnosis System.