Profisafe Address Types - Siemens SIMATIC S7-1200 Safety Programming Manualline

2 Configuring Fail-Safe Controllers
2.2

PROFIsafe address types

The PROFIsafe address is used to uniquely address F-I/O and protect standard
addressing mechanisms such as IP addresses. Uniqueness is defined differently
for F-I/O of PROFIsafe address type 1 and F-I/O of PROFIsafe address type 2.
Table 2-1: Differences between the PROFIsafe address types
PROFIsafe address type 1

The uniqueness of the PROFIsafe
address is ensured only by the F-
destination address.

The F-destination address must be
unique throughout the network and the
CPU.

In the safety summary, each F-
destination address has to be checked
for network- and CPU-wide uniqueness
by making sure that the F-destination
address ranges of all F-CPUs do not
overlap.

The F-destination address and the F-
source address are included in the
safety program's CRC.
You must ensure that each PROFIsafe address is unique.
The ever increasing networking of plants and plant sections – especially if
configured separately – makes accurate planning of the PROFIsafe address
assignment all the more necessary.
The use of F-I/O of PROFIsafe address type 2 makes handling PROFIsafe
addresses easier. With mixed configurations or pure address type 1 configurations,
however, one has to be more careful.
Recommendation

Already at the outset of the project, look at possible communication
relationships and network topologies. Consult with the parties involved to
derive measures for assigning PROFIsafe addresses.

Assign separate address ranges to PROFIsafe address types 1 and 2:
–
Assign a low number range to F-I/O of PROFIsafe address type 1
–
Assign a high number range to F-I/O of PROFIsafe address type 2.

Always define unique F-source addresses for all F-CPUs. This makes both
working across projects and later extensions easier.
Safety Programming Guideline
Entry ID: 109750255, V1.0, 10/2017
PROFIsafe address type 2

The uniqueness of the PROFIsafe
address is ensured by combining the F-
source address and the F-destination
address.

The F-destination address must be
unique throughout the CPU and differ
from all other F-destination addresses
of PROFIsafe address type 1 in the
same network.

The F-destination address used for the
F-I/O of an F-CPU must be unique
throughout the network.

The F-destination address and the F-
source address are included in the
safety program's CRC.
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