Siemens SIRIUS 3RK3 Equipment Manual page 289

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-specific 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-specific diagnostics must then also be
deactivated.
The following table shows the length of the DP diagnosis to be set when deselecting diagnoses:
Diagnostic type
ID-specific diagnosis
Module status
Channel-specific diagnosis
ID-specific diagnosis
Module status
Channel-specific diagnosis
ID-specific diagnosis
Module status
Channel-specific diagnosis
ID-specific diagnosis
Module status
Channel-specific diagnosis
Byte arrangements
When data longer than one byte is stored, the bytes are arranged as follows ("big endian"):
SIRIUS 3RK3 Modular Safety System
Equipment Manual, 07/2020, NEB926253002000/RS-AC/006
7.5 Diagnostics using PROFIBUS
Activated Deactivated
X ‑
X ‑
X ‑
X ‑
X ‑
‑ X
X ‑
‑ X
‑ X
‑ X
‑ X
‑ X
Diagnostics / service
Length
42
24
12
6
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