Debugging functions, diagnostics and troubleshooting
10.7 Diagnostics of DP CPUs
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
10-21
10.7.2
Reading out slave diagnostic data
The slave diagnostic data is compliant with EN 50170, Volume 2, PROFIBUS. Depending on
the DP master, diagnostic data for all DP slaves conforming to standard can be read with
STEP 7.
Diagnostic addresses for the receiving station with direct data exchange
For direct data exchange, you assign a diagnostic address in the receiving station:
PROFIBUS
Diagnostic address
CPU 31x-2 as sender
CPU 31x-2 as receiver
In this figure, you see that assign a diagnostic address to the receiving station in your
configuration. The receiving station receives information about the status of the transmitting
station or about a bus interruption by means of this diagnostic address.
Reading out the diagnostic data
The table below shows you how the various DP master systems can read diagnostic
information from a slave.
Table 10-12 Reading out diagnostic data in the master system, using STEP 5 and STEP 7
Automation system with
DP master
Blocks or registers in STEP 7 Application
Further Information
SIMATIC S7/M7
"DP slave diagnostics" tab
Output of slave diagnostic
data in plain text to a
STEP 7 user interface
Found under the keyword
Hardware
diagnostics
in the STEP 7 Online
Help and in the
Programming
STEP 7
Manual
SFB 54 "RALRM"
Reading additional
interrupt information from
a DP slave or local
module from the relevant
OB.
System and Standard Functions
Reference Manual
SFC 13 “DP NRM_DG”
Reading slave diagnostic
data
(stored in the data area of
the user program)
System and Standard Functions
Reference Manual
SFC 51 “RDSYSST”
Reading SSL sublists. In
the diagnostic interrupt,
call SFC 51 with the SSL
ID W#16#00B4, and then
read out the SSL of the
slave CPU.
System and Standard Functions
Reference Manual