Table of Contents
Advertisement
5.2 Diagnostic information
Profinet supports integrated diagnosis concept, each individual error occurred at the
same time or some errors are transferred from IO devices to the IO controller. The
following steps can be carried out for the diagnosis: response to the error (for
interrupt event-driven diagnosis and evaluation), check the current status of
automation system (status-driven diagnosis). Users can access to SFB/SFC in Step7 to
evaluate the diagnostic information:
1) Diagnosis with the SFB52 in the OB1
The diagnostic data record in the system offers a diagnostic capability with additional
detailed information, and the system function block SFB52 ("RDREC") is used for
reading these data records.
When called, the system function block addresses the station to be diagnosed and
indicates the data record to be read as the INDEX parameters. If there is no
diagnostic information, the system function block is executed without output.
Since SFB 52 "RDREC" is an SFB that works asynchronously, i.e., the execution spans
several SFB calls, the block can only be used in cyclic operation. A use of the block in
an interrupt OB or a timed interrupt OB is not advisable. Aside from the exact
position of the error, the diagnostic data record of SFB 52 also includes information
on the occurred error type. This information can be evaluated for further analysis
purposes.
You define the maximum number of bytes to read by setting the MLEN variable, so
you should select a RECORD target range of at least the same length as defined in
MLEN. Output parameter VALID = TRUE indicates the successful transfer of the
record to the target area RECORD. Output parameter LEN contains the length in
[bytes] of the read data. Output parameter ERROR reports any errors detected during
record transfer. ERROR =TRUE and the error information is written to output
parameter STATUS when an error is detected.
2) Diagnosis with the SFB54 in the OB82
SFB54 "RALARM" evaluates received interrupt data and all corresponding
information from peripheral modules or Profinet devices, and then the information is
provided to the output parameters.
The information with additional detailed information includes both the information
of the starting interrupt OB and the information of the interrupt source. Call
"RALRM" only within the interrupt OB started by the CPU operating system as a
Spider67 Profinet– Extensible industrial fieldbus I/O System
61 / 62
Advertisement
Table of Contents
