Replacement of failed components during redundant operation
13.3 Replacement of components of the distributed I/O on PROFIBUS DP
CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC
237
Procedure
Proceed as follows to replace a DP slave:
Step
What to do?
How does the system react?
1
Turn off the supply for the DP slave.
With one-sided I/O: OB 86 and OB85 are
called for access errors during the PA up-
date.
With switched I/O: OB70 is called (incoming
event), the LED REDF lights up.
2
Remove the bus connector.
–
3
Replace the DP slave.
–
4
Plug the bus connector back in and turn the
power supply back on.
•
The CPUs process the rack failure OB
86 synchronously (outgoing event).
•
With switched I/O: OB70 is called (out-
going event), the LED REDF goes out.
•
The associated DP master can address
the DP slave.
13.3.4
Replacement of PROFIBUS DP cables
Starting situation
Failure
How does the system react?
The S7-400H is in redundant system mode and
the PROFIBUS DP cable is defective.
•
With single-channel one-sided I/O:
Rack failure OB (OB 86) is started (incoming
event). The DP master can no longer process
connected DP slaves
(station failure).
The LED BUS1F flashes.
•
With switched I/O:
I/O redundancy error OB (OB 70) is started
(incoming event). DP slaves are addressed
via the DP master of the partner.
The LED BUS1F and the LED REDF are
flashing.