Siemens Simatic S7-300 CPU 31xC and CPU 31x S7-300 - Manual (Page 200)

Technical data of CPU 31x
7.7 CPU 317-2 PN/DP
CPU 31xC and CPU 31x, Technical data
7-34
Manual, Edition 08/2004, A5E00105475-05
Technical data
IEC Timers
Yes
• Type SFB
• Number Unlimited
(limited only by RAM size)
Data areas and their retentivity
Flag bits
4096 bytes
• Retentive memory Configurable
• Default retentivity From MB0 to MB15
Clock flag bits 8 (1 byte per flag bit)
Data blocks
•
Number 2047
(DB 1 to DB 2047)
• Length 64 KB
• Non-Retain support (configured retention) Yes
Local data per priority class max. 1024 bytes
Blocks
Total
2048 (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 64 KB
Nesting depth
• Per priority class 16
• additional within an error OB 4
FBs See the Instruction List
• Number 2048
(FB 0 to FB 2047)
• Length 64 KB
FCs See the Instruction List
• Number 2048
(FC 0 to FC 2047)
• Length 64 KB
Address areas (I/O)
Total I/O address area
max. 8192 bytes/8192 bytes
(can be freely addressed)
Distributed max. 8192 bytes
I/O process image
•
Configurable 2048/2048
• Default 256/256
Digital channels 65536/65536
of those local Max. 1024