Settings in STEP 7
Set the properties of the PROFIBUS subnet in STEP 7: The DP alarm mode must be set to DPV1 for
operation downstream of a Y link. Individual PROFIBUS diagnostics can be deselected in the
device-specic parameters. The length of the diagnostics frame must be adjusted accordingly.
If all diagnostics are transmitted, the length of the diagnostics frame is 42 bytes. The diagnostics
must only be deselected from bottom to top in the hierarchy. For example, it is not permissible
to deselect only the module status; the channel-specic diagnostics must then also be
deactivated.
The following table shows the length of the DP diagnosis to be set when deselecting diagnoses:
Diagnostic type Activated Deactivated Length
ID-specic diagnosis X ‑ 42
Module status X ‑
Channel-specic diagnosis X ‑
ID-specic diagnosis X ‑ 24
Module status X ‑
Channel-specic diagnosis ‑ X
ID-specic diagnosis X ‑ 12
Module status ‑ X
Channel-specic diagnosis ‑ X
ID-specic diagnosis ‑ X 6
Module status ‑ X
Channel-specic diagnosis ‑ X
Byte arrangements
When data longer than one byte is stored, the bytes are arranged as follows ("big endian"):
'DWDW\SH%\WHDUUDQJHPHQW
%\WH
%\WH
+LJK%\WH
+LJK%\WH
/RZ%\WH
+LJK%\WH
/RZ%\WH
+LJK:RUG
/RZ:RUG
%\WH
%\WH
%\WH
%\WH
%\WH
%\WH
%\WH
%\WH
%\WH
:RUG
'RXEOH:RUG':RUG
/RZ%\WH
Diagnostics / service
7.5 Diagnostics using PROFIBUS
SIRIUS 3RK3 Modular Safety System
Equipment Manual, 07/2020, NEB926253002000/RS-AC/006 289