What Should I Note At The System Planning Stage? - Siemens SIMATIC S7-400H Manual

Notice
The addition or removal of the IM460 and IM461 interface modules, the external
DP master interface module CP443-5 Extended and the associated connecting
cables is only permitted in a deenergized state.
• Adding or removing components of the remote input/output station, such as
– DP slaves with a redundant interface module (e.g. ET 200M, DP/PA link or Y
link)
– One-way DP slaves (in any DP master system)
– Modules in modular DP slaves
– DP/PA couplers
– PA devices
• Use of a free channel on an existing module
• Reconfiguration of a module
• Changing certain CPU parameters
• Changing the parameters of an installed module
• Changing the Memory Components of the CPU
With all modifications observe the rules for the configuration of a fault-tolerant
station (see Section 9.2.1).
Refer to the information text in the "Hardware Catalog" window to determine which
ET 200M modules (signal modules and function modules) can be reconfigured
during ongoing operation. The special reactions of individual modules are
described in the respective technical documentation.

What should I note at the system planning stage?

In order for switched I/O to be able to be expanded during operation the following
points are to be taken into account at the system planning stage:
• In both cables of redundant DP master system sufficient numbers of branching
points are to be provided for spur lines or dividing points (spur lines are not
permissible at transmission rates of 12 million bps). These may either be
provided at regular intervals or at all well accessible points.
• Both cables are to 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 excellent 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.
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
Modifying the System During Operation
11-3