Siemens SIMATIC S7-400H - STEP 7, Step 6: Switch to CPU with Modified Configuration

Modifying the System During Operation
11-28
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
11.4.6 STEP 7, Step 6: Switch to CPU with Modified Configuration
Initial situation
The modified hardware configuration is loaded into the standby CPU.
Procedure
1. In SIMATIC Manager, select a CPU of the fault-tolerant system, and choose the
PLC > Operating Mode menu command.
2. In the Operating Mode dialog box, click the Toggle button.
3. In the Toggle dialog box, select the option with modified configuration and
click the Toggle button.
4. Confirm the query that follows with OK.
Result
The standby CPU links up, is updated and becomes the master. The former
master CPU switches to STOP mode, the fault-tolerant system works with the new
hardware configuration in single mode.
Behavior of the I/O
Type of I/O One-way I/O of previous
master CPU
One-way I/O of new
master CPU
Switched I/O
Added I/O modules Are not addressed by the
CPU.
Are configured and updated by the CPU.
Output modules briefly output the substitute values
configured.
I/O modules that
continue to be
present
Are no longer addressed
by the CPU.
Output modules output the
configured substitute or
holding values.
Are re-parameterized
1)
and updated by the CPU.
Continue to work without
interruption.
Added DP stations Are not addressed by the
CPU.
as for added I/O modules (see above)
1) Central modules are first reset in addition. Output modules briefly output 0 during this time (instead of the
substitute or holding values configured).