Diagnostic Buffer Of The Module - Siemens SIMATIC FM 351 Manual

Diagnostics
11.6

Diagnostic Buffer of the Module

The diagnostic buffer of the module contains a maximum of 9 diagnostic entries
and is organized as a ring buffer.
A diagnostic event is written to the buffer when a message (error) "entering state"
is detected. This can be a synchronous error (data error, operator error) or an
asynchronous error (operating error, diagnostic error). One problem can also
cause several entries as follow-on errors. Messages for events "leaving state" do
not cause entries in the diagnostic buffer.
The following is specified for each diagnostic event:
Status (always entering state)
Internal error
External error
Error class
Error number
Channel number
Incremental dimension number (for incremental dimension errors)
If a diagnostic event is written to the diagnostic buffer, the return signal DIAG=1 is
set in all channels being used.
The entire diagnostic buffer can be transferred to a data block (diagnostic DB)
using FC ABS_DIAG or displayed in the error evaluation dialog of the configuration
software. If the diagnostic buffer is read, the module sets the return signal
DIAG=0.
Note
If the diagnostic buffer is read simultaneously by FC ABS_DIAG and the error
evaluation dialog, it is possible that a newly entered diagnostic event is not
detected by the program.
11-10
FM 351 Positioning Module
C79000-G7076-C351-02