Siemens Simatic S7-300 CPU 31xC and CPU 31x S7-300 - Manual (Page 175)

Technical data of CPU 31x
7.3 CPU 314
CPU 31xC and CPU 31x, Technical data
Manual, Edition 08/2004, A5E00105475-05
7-9
Technical data
Data areas and their retentivity
Flag bits
256 bytes
• Retentive memory Yes
• Default retentivity MB0 to MB15
Clock flag bits 8 (1 byte per flag bit)
Data blocks
• Number 511
(DB 1 to DB 511)
• Length 16 KB
Local data per priority class Max. 510
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 16 KB
Nesting depth
• Per priority class 8
• additional within an error OB 4
FBs See the Instruction List
• Number 512
(FB 0 to FB 511)
• Length 16 KB
FCs See the Instruction List
• Number 512
(FC 0 to FC 511)
• Length 16 KB
Address areas (I/O)
Total I/O address area
Max. 1024 bytes/1024 bytes (can be freely
addressed)
I/O process image 128 bytes/128 bytes
Digital channels Max. 1024
of those local Max. 1024
Analog channels Max. 256
of those local Max. 256
Assembly
Racks
Max. 4
Modules per rack 8
Number of DP masters
• Integrated None
• via CP Max. 1