Siemens S7-400 - Sequence in the Module Subassembly; Possible Applications of the M7-400 Modules

Assembling the M7-400
8-3
S7-400 and M7-400 Programmable Controllers Hardware and Installation
A5E00069481-04
Table 8-1 Sequence in the Module Subassembly
CPU
Slot Slot Slot
Slot n and n + 1 for Double-Width
CPUs
n + 2 n + 3 n + 4
EXM 478 - -
EXM 478 EXM 478 -
EXM 478 EXM 478 EXM 478
EXM 478 EXM 478 ATM 478
EXM 478 ATM 478 ATM 478
EXM 478 ATM 478 -
ATM 478 - -
CPU 486-3, CPU 488-3
ATM 478 ATM 478 -
ATM 478 ATM 478 ATM 478
MSM 478 - -
EXM 478 MSM 478 -
EXM 478 EXM 478 MSM 478
EXM 478 MSM 478 ATM 478
MSM 478 ATM 478 ATM 478
MSM 478 ATM 478 -
Note
Establish whether there are additional regulations applying to all modules not
described in this manual.
Table 8-2 shows which modules can be used in the different racks.
Table 8-2 Possible Applications of the M7-400 Modules
Racks
Modules
UR1, UR2
as
Central
Rack
UR1, UR2
as
Expansion
Rack
CR2 ER1, ER2
Central Processing Units (CPUs)  -  -
Expansion Module (EXM) 
*
- 
*
-
AT Adapter Module (ATM) 
*
- 
*
-
Mass Storage Module (MSM) 
*
- 
*
-
* Can only be inserted in conjunction with the CPU.