Configuring Hardware and Communication Connections STEP 7.pdf

14.6 Downloading a Changed HW Configuration to an
S7-400H Station
Downloading
With an H-station, you can download a changed HW configuration, without the Hstation
having to go in STOP mode. To ensure that the H-station can modify the
process without interruption during the download; that is, that one of the two CPUs
is always in RUN mode, you must absolutely follow the prescribed sequence of
operations. For a complete, detailed description of the functions and procedures,
refer to the following manual: Automation System S7-400H Fault-Tolerant
Systems.
As of STEP 7 V5.3 Service Pack 2, you have the option of letting the download
procedure after changing the hardware configuration run almost completely
automatically. STEP 7 will automatically prepare the next action required. To have
this action carried out, you will only have to confirm the step by clicking the "Next"
button.
You can also configure this function so that the switchover from one CPU to the
other happens mostly automatically.
Requirements and Restrictions for an Automatic Download
• Downloading a changed HW configuration to an S7-400 H-station can only be
done in HW Config.
• The changed configuration can only be downloaded to CPUs. The configuration
will not be downloaded to any modules that receive their configuration data
directly (FM 456-2, FM 456-4).
• When downloading, you cannot reconfigure node addressees; the node
addresses configured for the H-CPUs must match the existing node addresses.
• At least one of the two H-CPUs must be able to be reached online.
• The H-station does not necessarily have to be in redundant mode; it is sufficient
to have one of the CPUs in RUN mode. For an automated download, the Hstation
will be placed in redundant mode when the reserve CPU is restarted.
• The operating mode switch for both CPUs must be in RUN position (RUN-P for
CPUs with a keyswitch).
If all of these requirements are not met, then the "Download station configuration in
RUN mode" option will not be available.
Configuring Hardware and Communication Connections with STEP 7
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