Siemens SIMATIC NET S7-300 Manual page 157

Messages in the Diagnostic Buffer
As a result of FETCH/WRITE access, negative acknowledgments from the S7
CPU are possible. This then leads to corresponding connection-oriented entries in
the diagnostic buffer that you can read out with NCM Diagnostics (see Section
8.5).
Table 5-8
Coding
01
03
05
06
07
0A
FF
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
Message Coding in the Diagnostic Buffer with FETCH/WRITE
Hardware fault
H
Object access is not permitted.
H
Invalid address (syntax ID, area, type, bit number)
H
Data type not currently supported
H
Data type is not consistent.
H
The object does not exist or the end of the area has been excee-
H
ded.
Internal protocol error
H
5 Configuring Communication Connections
Meaning
A -157