Installation manual

Assembling the M7-400
8-54
S7-400 and M7-400 Programmable Controllers Hardware and Installation
A5E00069481-04
8.8.3 Replacing Memory Cards in a CPU
Introduction
To be able to replace MEM 478 memory cards in a CPU, you must remove the
module assembly from the rack (see Section 8.8.2, page 8-49). It is not necessary
to disassemble the module assembly because the CPU is always situated on the
left end of the assembly, and the slot for the memory cards is therefore accessible.
Note
With both CPUs, a DRAM card of the same size must be inserted in each of
Slots 1 and 2.
Only use the memory cards intended for the particular CPU.
!
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 replacing memory cards.
Replacing Memory Cards for Main Memory and OSD
To remove a memory card from a CPU slot, follow the steps outlined below:
1. Remove the cover from the upper left side of the CPU by loosening the three
screws.
2. Press both lateral retaining springs to release the lock of the desired memory
card. The card is raised at an angle of 45° (see Figure 8-28).
3. Remove the memory card from the connector (see Figure 8-28).
4. Push the new memory card at an angle of about 45° into the free connector as
far as it will go (see Figure 8-28).
5. Press the new memory card on the protruding side in the direction of the PCB
until it engages with the two retaining springs (see Figure 8-28).
6. Fit the cover on the upper left side of the CPU by securing it with three screws.