Siemens SIMATIC S7-400H - Types of Memory Cards; Types of Memory Cards for the S7-400; What the Memory Card Contains; Which Type of Memory Card to Use

Installation of a CPU 41x-H
4-18
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
What the Memory Card Contains
The following data can be stored in the memory card:
• User program, i.e. blocks (OBs, FBs, FCs, DBs) and system data
• Parameters that determine the behavior of the CPU
• Parameters that determine the behavior of the I/O modules.
• As of STEP 7 V5.1 the complete project files on suitable memory cards.
Types of Memory Cards for the S7-400
Two types of memory card are used in the S7-400:
• RAM cards
• Flash cards (FEPROM cards)
Note
Third-party memory cards cannot be used in the S7-400.
Which Type of Memory Card to Use
Whether you use a RAM card or a Flash card depends on how you intend to use
the memory card.
Table 4-4 Types of memory cards
If You ...
...Then
want to store the data in RAM and you want
to modify your program during RUN or
RUN-P mode,
use a RAM card
want to store your user program long-term
on memory card also when the power is
switched off (without backup or outside the
CPU),
use a Flash card