Siemens SIMATIC PCS 7 CPU 410-5H System Manual page 152

System modifications during redundant operation
10.1 System modifications during operation
What should I consider during system planning?
For switched I/O to be expanded during operation, the following points must be taken into
account already at the system planning stage:
● In both cables of a redundant DP master system, sufficient numbers of branching points
are to be provided for spur lines or isolating points (spur lines are not permitted for
transmission rates of 12 Mbit/s). These branching points can be spaced or implemented
at any points that can be accessed easily.
● Both cables must be uniquely identified so that the line which is currently active is not
accidentally cut off. This identification should be visible not only at the end points of a
line, but also at each possible new connection point. Different colored cables are
especially suitable for this.
● Modular DP slave stations (ET 200M), DP/PA links and Y links must always be installed
with an active backplane bus and fitted with all the bus modules required wherever
possible, because the bus modules cannot be installed and removed during operation.
● The removal of the terminal modules with the ET200iSP should have sufficient reserves
and be fitted with unconfigured reserve modules.
● Always terminate both ends of PROFIBUS DP and PROFIBUS PA bus cables using
active bus terminating elements in order to ensure proper termination of the cables while
you are reconfiguring the system.
● PROFIBUS PA bus systems should be built up using components from the SpliTConnect
product range (see interactive catalog CA01) so that separation of the lines is not
required.
Modification of the hardware configuration
With a few exceptions, all elements of the configuration can be modified during operation.
Usually configuration changes will also affect the user program.
The following must not be changed by means of system modifications during operation:
● Certain CPU parameters (for details refer to the relevant sections)
● PN configurations
● The transmission rate (baud rate) of redundant DP master systems
● S7 and S7 H connections
Modifications to the user program and the connection configuration
The modifications to the user program and connection configuration are loaded into the
target system in redundant system state. More detailed information can be found in the
PCS 7, Configuration Manual
152
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CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB