Siemens SIMATIC S7-400 Hardware And Installation Manual page 237

Note
The connectors to accept the memory cards are coded (see Figure 8-29).
Do not apply force when fitting the memory cards.
2
5
Figure 8-28 Removing Memory Cards from the CPUs
Recess
Figure 8-29 3.3 V Memory Card
S7-400 and M7-400 Programmable Controllers, Installation Manual
C79000-G7076-C424-01
www.gkbpx.com
4
3
Slot 1
Slot 2
3.3 V DRAM memory card
(for main memory)
Slots 1 and 2
Assembling the M7-400
8-55