Siemens Simatic S7-300 CPU 31xC Series Installation And Operating Instructions Manual page 118

Addressing
7.1 Slot-specific addressing of modules
The figure below shows the slots of an S7-300 and the corresponding module start
addresses:
Rack 3 (EM)
Digital module start address
Analog module start address
Rack 2 (EM)
Digital module start address
Analog module start address
Rack 1 (EM)
Digital module start address
Analog module start address
Rack 0
(CU)
Slot number
Digital module start address
Digital module start address
7-2
IM
Slot number 3
IM
3
Slot number
IM
Slot number
3
SF SF
SIEMEN S
BUSF BUSF
DC5V DC5V
FRCE FRCE
RUN RUN
STOP STOP
PS CPU
2
1
SM SM SM SM SM
4 5 6 7
108
96 100 104
640 656 672 688
SM SM SM SM SM
4 5 6 7
64 68 72 76
512 528 544 560
SM SM SM SM SM
4 5 6 7
32 36 40 44
384
400 432
416
IM
SM SM SM SM SM
3 4 5 6 7
0 4 8 12
256 272 288 304
Operating Instructions, Edition 08/2004, A5E00105492-05
Not CPU 31xC
SM SM SM SM
8 9 10 11
116
112 120 124
704 720 736 752
SM SM SM SM
8 9 10 11
80 84 88 92
576 592 608 624
SM SM SM SM
8 9 10 11
48 52 56 60
448 464 480 496
SM SM SM SM
8 9 10 11
16 20 24 28
320 336 352 368
S7-300, CPU 31xC and CPU 31x: Installation