Siemens SIMATIC S7-400 Hardware And Installation Manual page 195

Frame of card slot with
mounting hole
Figure 8-3
Covering Unused Submodule Slots
On delivery, only the upper submodule slot is open in the central and expansion
racks. All other card slots are covered. The cover is secured to the frame of the
card slot with screws.
Loosen the screws and remove the cover to insert more than one interface
submodule in an expansion module.
S7-400 and M7-400 Programmable Controllers, Installation Manual
C79000-G7076-C424-01
www.gkbpx.com
EXM 478
Inserting an Interface Submodule in an Expansion Module
Assembling the M7-400
Guides
8-13