Failure And Replacement Of Components Of The Distributed I/Os; Failure And Replacement Of A Profibus-Dp Master - Siemens SIMATIC S7-400H System Manual

Failure and replacement of components during operation

13.3 Failure and replacement of components of the distributed I/Os

13.3 Failure and replacement of components of the distributed I/Os
Which components can be replaced?
The following components of the distributed I/Os can be replaced during operation:
● PROFIBUS-DP master
● PROFIBUS-DP interface module (IM 153-2 or IM 157)
● PROFIBUS-DP slave
● PROFIBUS-DP cable
13.3.1

Failure and replacement of a PROFIBUS-DP master

Starting situation
Failure
The S7-400H is in redundant mode and a DP
master module fails.
Procedure
To replace a PROFIBUS-DP master:
Step
1
2
3
4
5
196
Note
Replacing I/O and function modules located in a distributed station is described in
Section Failure and replacement of an input/output or function module (Page 189).
What has to be done?
Turn off the power supply of the
central rack.
Unplug the Profibus–DP cable of the
affected DP master module.
Replace the affected module.
Plug the Profibus–DP cable back in.
Turn on the power supply of the
central rack.
How does the system react?
With single-channel, one-sided I/O:
•
DP master can no longer process connected
DP slaves.
With switched I/O:
•
DP slaves are addressed via the DP master
of the partner.
How does the system react?
The fault-tolerant system switches to single
mode.
–
–
–
CPU performs automatic LINK-UP and
•
UPDATE.
CPU changes to RUN and operates as the
•
standby CPU.
System Manual, 09/2007, A5E00267695-03
S7-400H