Siemens S7-400 Benutzerhandbuch

M7-400 Expansions

12-5

S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07

Permissible Combinations

You can see from the table below which expansions can be connected to the
programmable M7-400 modules.

Table 12-1 Expansion Possibilities of the CPU 486-3, CPU 488-3, or FM 456

Programmable M7-400 Module

Slot

Slot n in the Case of Single-Width Modules

n + 1

n + 2

n + 3

Slot n and n+1

in the Case of Double-Width Modules

n + 2

n + 3

n + 4

–

EXM 478

–

EXM 478

–

EXM 478

ATM 478

EXM 478

ATM 478

EXM 478

ATM 478

–

CPU 486 3 CPU 488 3 FM 456 4

ATM 478

–

CPU 486-3, CPU 488-3, FM 456-4

ATM 478

–

ATM 478

MSM 478

–

EXM 478

MSM 478

–

EXM 478

MSM 478

EXM 478

MSM 478

ATM 478

MSM 478

ATM 478

MSM 478

ATM 478

–

Rules for the Combinations

The following rules apply for expansions from left to right after a CPU or application
module (slots n + 1, n + 2, n + 3 or n + 2, n + 3, n + 4):

1. Up to 3 EXM 478 expansion modules

2. Max. 1 MSM 478 mass storage module

(that is, always after the CPU 486-3, CPU 488-3, FM 456, or EXM 478)

3. Up to 3 ATM 478 AT adapter modules

(that is, always after the CPU 486-3, CPU 488-3, FM 456, EXM 478, or
MSM 478)

In total, a CPU or application module can be expanded with up to three modules.