Step 7, Step 8: Editing And Downloading The User Program - Siemens SIMATIC S7-400H System Manual

14.5.8

STEP 7, step 8: Editing and downloading the user program

Starting situation
The fault-tolerant system is operating with the new hardware configuration in redundant
mode.
Restrictions
Any attempts to modify the structure of an FB interface or the instance data of an FB in
redundant mode will lead to a system STOP at both CPUs.
Procedure
1. Adapt the program to the new hardware configuration.
2. Download only the program changes to the PLC.
3. Configure the interconnections for the new CPs on both communication partners and
Result
The fault-tolerant system processes the entire system hardware with the new user program
in redundant mode.
S7-400H
System Manual, 09/2007, A5E00267695-03
CAUTION
You can add, edit or remove OBs, FBs, FCs and DBs.
download them to the PLC.
System modifications in operation
14.5 Adding components in STEP 7
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