Siemens Simatic S7-300 CPU 31xC and CPU 31x S7-300 User Manual
Page 170
Technical data of CPU 31x
7.2 CPU 312
CPU 31xC and CPU 31x, Technical data
7-4
Manual, Edition 08/2004, A5E00105475-05
Technical data
Data areas and their retentivity
Flag bits
128 bytes
•
Retentive memory
Yes
•
Default retentivity
MB0 to MB15
Clock flag bits
8 (1 byte per flag bit)
Data blocks
511
(DB 1 to DB 511)
•
Length
16 KB
Local data per priority class
max. 256 bytes
Blocks
Total
1024 (DBs, FCs, FBs)
The maximum number of blocks that can be
loaded may be reduced if you are using another
MMC.
OBs
See the Instruction List
•
Length
max. 16 KB
Nesting depth
•
Per priority class
8
•
additional within an error OB
4
FBs
Max. 512
(FB 0 to FB 511)
•
Length
max. 16 KB
FCs
Max. 512
(FC 0 to FC 511
•
Length
max. 16 KB
Address areas (I/O)
Total I/O address area
1024 bytes /1024 bytes
(can be freely addressed)
I/O process image
128 bytes/128 bytes
Digital channels
Max. 256
of those local
Max. 256
Analog channels
Max. 64
of those local
Max. 64
Assembly
Racks
Max. 1
Modules per rack
Max. 8
Number of DP masters
•
Integrated
None
•
Via CP
1