Failure And Replacement Of A Profibus Dp Slave; Failure And Replacement Of Profibus Dp Cables - Siemens SIMATIC S7-400H System Manual

Failure and replacement of components during operation
16.3 Failure and replacement of components of the distributed I/Os
16.3.3

Failure and replacement of a PROFIBUS DP slave

Starting situation
Failure
The S7-400H is in redundant system mode and a
DP slave fails.
Procedure
Proceed as follows to replace a DP slave:
Step
1
2
3
4
16.3.4

Failure and replacement of PROFIBUS DP cables

Starting situation
Failure
The S7-400H is in redundant system mode and
the PROFIBUS DP cable is defective.
278
What has to be done?
Turn off the supply for the DP slave.
Remove the bus connector.
Replace the DP slave.
Plug the bus connector back in and turn the
power supply back on.
How does the system react?
Both CPUs report the event in the diagnostic
buffer and via the appropriate OB.
How does the system react?
–
–
–
The CPUs process the rack failure OB

86 synchronized with each other
(outgoing event)
The associated DP master can address

the DP slave.
How does the system react?
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).
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.
System Manual, 03/2012, A5E00267695-11
S7-400H