Siemens S7-1200 PROFIBUS - Device-Specific Diagnostics in DP-V0

Diagnostics and upkeep
5.1 Diagnostics
SIMATIC CM 1242-5
38 Operating Instructions, 01/2023, C79000-G8976-C245-06
Table 5- 10 Structure of the bytes for module-specific diagnostics data
Byte
Bit assignment
Bit
7
6
5
4
3
2
1
0
4
Module status 4
Module status 3
Module status 2
Module status 1
5
Module status 8
Module status 7
Module status 6
Module status 5
...
...
...
...
...
62
Module status 236
Module status 235
Module status 234
Module status 233
The status bits are coded as follows:
Table 5- 11 Meaning of the values of the status bits
Value
Meaning
00
Data valid
01
Data invalid - error (for example short-circuit)
10
Data invalid - wrong module
11
Data invalid - no module plugged in
5.1.5 Device-specific diagnostics in DP-V0
With standard DP slaves (DP-V0), this field contains general diagnostics information such as
overtemperature, undervoltage or similar. The coding is specified for the specific device by
the slave manufacturer. For further evaluation, the Ident_Number of the slave is required
(bytes 4...5 of the standard diagnostics).
The device-specific diagnostics data of DP-V0 slaves is structured as follows:
Byte 0: Header
The two most significant bits have the value 00. This identifies the "module-specific
diagnostics data" field as a whole.
The remaining six bits indicate the length of the data field including byte 0.
Bytes 1...62: Module-specific diagnostics data
Diagnostics is slot-specific.
The structure is the same as for the diagnostics data in DP-V1, see
section Device-specific diagnostics in DP-V1 (Page 35),
bytes 4..62: Module-specific diagnostics with "status type" and "module status"