Replacing Memory Cards - Siemens S7-400 Installation Manual

7.11

Replacing Memory Cards

Memory Expansion
The CPU 417-4 and CPU 417-4 H memory modules are expandable. Take note of
the following rules for the expansion procedure:
1. If you are inserting only one module, it has to be inserted on slot 1.
2. A second module may only be inserted if a module of 4 Mbytes is inserted on
slot 1.
The following combinations are thus possible:
In order to be able to replace memory cards in a central processing unit, you have
to remove the CPU from the rack (see section 7.3).
Warning
!
The modules can be damaged.
Failure to observe ESD guidelines can result in damage to both the CPU and
memory cards.
Observe the ESD guidelines when fitting memory cards.
Only use the memory cards intended for the particular CPU.
Fitting Memory Cards in the CPU
Proceed as follows:
1. Remove the cover from the left side of the CPU by loosening the three screws.
2. Push the first memory card down through an angle of approximately 45
slot 1 (see Figure 7-1). Note the cutout at the front of the card (polarity reversal
protection).
3. Push the memory card down until the tabs in the slot slide into the
corresponding cutouts on the side of the card. Make sure that the metal flag at
the end of the card lies on the metal edge of the module.
4. If necessary, insert the second memory card in slot 2 in the same way (see
Figure 7-1).
5. Fit the cover on the upper left side of the CPU by securing it with three screws.
S7-400 and M7-400 Programmable Controllers Hardware and Installation
A5E00069481-04
Slot 1
2 Mbytes
4 Mbytes
4 Mbytes
4 Mbytes
Maintenance
Slot 2
–
–
2 Mbytes
4 Mbytes
o
into
7-19