Step 7: Modify And Download The User Program - Siemens SIMATIC PCS 7 System Manual

Type of I/O
Added DP stations as for added I/O modules
1) Central modules are first reset. Output modules briefly output 0 during this time (instead of the
configured substitute or hold values).
Reaction to monitoring timeout
If one of the monitored times exceeds the configured maximum, the update is canceled. The
fault-tolerant system remains in single mode with the previous master CPU and, assuming
certain conditions are met, attempts the link-up and update later. For additional information,
refer to section Time monitoring (Page 117).
10.3.7

Step 7: Modify and download the user program

Starting situation
The fault-tolerant system is operating with the new hardware configuration in redundant
system mode.
The following program modifications are not possible in redundant system mode and result
in the system mode Stop (both CPUs in STOP mode):
• Structural modifications to an FB interface or the FB instance data.
• Structural modifications to global DBs.
• Compression of the CFC user program.
Before the entire program is recompiled and reloaded due to such modifications the
parameter values must be read back into the CFC, otherwise the modifications to the block
parameters could be lost. You will find more detailed information on this topic in the
S7, Continuous Function Chart
Procedure
1. Adapt the program to the new hardware configuration. You can add the following
components:
– CFCs and SFCs
– Blocks in existing charts
– Connections and parameter settings
2. Assign parameters for the added channel drivers and interconnect them with the newly
assigned icons (see section Step 2: Modify the hardware configuration offline
(Page 147)).
CPU 410-5H Process Automation/CPU 410 SMART
System Manual, 09/2014, A5E32631667-AB
One-sided I/O of the
standby CPU
(see above)
CAUTION
System modifications during redundant operation
One-sided I/O of the
master CPU
Driver blocks are not yet present. Any interrupts
occurring are not reported.
manual.
10.3 Adding components
Switched I/O
CFC for
151