Siemens Simatic S7-300

S7-300 Automation System Module data
Manual, 08/2006, A5E00105505-04
B-1
B Diagnostics data of signal modules
B
B.1 B.1 Evaluating diagnostic data of signal modules in the user program
Introduction
This appendix describes the diagnostic data structure in system data. You should be
sufficiently familiar with this structure if you want to evaluate the diagnostics data of the
signal module in the
STEP 7 user program.
Diagnostic data are stored in data records
Module diagnostics data may have a length of max. 16 bytes, and are contained in data
records 0 and 1:
● Data record 0 contains 4 bytes of diagnostic data describing the current state of an
automation system.
● Data record 1 shares the same four bytes of diagnostics with data record 0, and contains
up to 12 bytes of module-specific diagnostics data.
Further references
For detailed information on the principles of evaluating diagnostics data of signal modules in
the user program, and on SFCs you may use in this context, refer to the
STEP 7 manuals.