I/O configuration variants
4.2 Fail-safe operation
CPU 410-5H Process Automation
56
System Manual, 09/2014, A5E31622160-AB
PROFINET IO is the innovative and open Industrial Ethernet standard for automation. It
enables fast reaction times and transmission of large data quantities.
PROFIsafe uses the PROFIBUS or PROFINET IO services for safe communication. A fail-
safe CPU 410 and the fail-safe I/O exchange both user data as well as status and control
information; no additional hardware is required for this.
PROFIsafe takes the following measures to counteract the various possible errors when
transferring messages.
Table 4- 2
Measures in PROFIsafe for error avoidance
Measure/
Error
Consecutive number
Time expectation with
acknowledgment
Identifier for sender
and receiver
Data backup CRC
Repetition
✓
Loss
✓
✓
Insertion
✓
✓
✓
Incorrect sequence
✓
Data falsification
✓
Delay
✓
Coupling of safety-
related messages and
standard messages
(masquerade)
✓
✓
✓
FIFO errors (first-in-
first-out data register
for maintaining the
sequence)
✓