Debugging functions, diagnostics and troubleshooting
10.3 Overview: Diagnostics
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
10-5
Error handling
Programming with foresight and, above all, knowledge and proper handling of diagnostic
tools puts you into an advantageous position in error situations:
•
You can reduce the effects of errors.
•
It makes it easier for you to locate errors (by programming error OBs, for example).
•
You can limit downtimes.
Diagnostics with LED display
SIMATIC S7 hardware offers diagnostics with LEDs.
These LEDs are implemented in three colors:
LED color
State of CPU
Green
Regular operation.
Example: Power is on.
Yellow
Non-regular operating status.
Example: Forcing is active.
Red
Fault.
Example: Bus error
LED flashing
Special event
Example: CPU memory reset
Two LEDs are used for Ethernet:
LED designation
Color
State
Meaning
LINK
Green Off
No other device is connected with the integrated
PROFINET interface of the CPU.
On
Another device (in most cases a switch) is connected to
the integrated PROFINET interface of the CPU, and the
physical connection is in place.
RX/TX
Yellow Off
No activity:
No data are transferred via the integrated PROFINET
interface of the CPU.
On
Activity:
Data are transferred via the integrated PROFINET
interface of the CPU.
Note: The LED flickers when small data volumes are
transferred.
Reference
Notes on diagnostics of I/O modules capable of diagnostics are found in the relevant
Manual.