Pcs 7, Step 5: Switch To Cpu With Modified Configuration; Behavior Of The I/O - Siemens SIMATIC S7-400H Manual

11.2.5

PCS 7, Step 5: 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 (see Chapter 6) 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
Added I/O modules Are not addressed by the
CPU.
I/O modules that Are no longer addressed
continue to be by the CPU.
present
Output modules output the
configured substitute or
holding values.
Added DP stations Are not addressed by the
CPU.
1) Central modules are additionally first reset. Output modules briefly output 0 during this time (instead of the
configured substitute or holding values).
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
One-way I/O of new
master CPU
Are configured and updated by the CPU.
Driver blocks are not yet present. Any process or
diagnostics interrupts occurring will be recognized but
not reported.
Are re-parameterized
and updated by the CPU.
as for added I/O modules (see above)
Modifying the System During Operation
master CPU
1)
Continue to work without
interruption.
Switched I/O
11-11