2 cpu 312c – Siemens Simatic S7-300 CPU 31xC and CPU 31x S7-300 User Manual
Page 113
Technical data of CPU 31xC
6.2 CPU 312C
CPU 31xC and CPU 31x, Technical data 
Manual, Edition 08/2004, A5E00105475-05 
6-3
6.2
CPU 312C
Technical data
Table 6-3
Technical data of CPU 312C
Technical data 
CPU and version 
Order number 
6ES7 312-5BD01-0AB0
•
Hardware version
01
•
Firmware version
V2.0
•
Associated programming package
STEP 7 as of V 5.2 + SP 1 
(please use previous CPU for STEP 7 V 5.1 + 
SP 3 or later)
Memory 
RAM 
•
Integrated
16 KB
•
Expandable
No
Load memory
Plugged in with MMC (max. 4 MB)
Data storage life on the MMC
(following final programming)
At least 10 years
Buffering
Guaranteed by MMC (maintenance-free)
Execution times 
Processing times of 
•
Bit operations
Min. 0.2 μs
•
Word instructions
Min. 0.4 μs
•
Fixed-point arithmetic
Min. 5 μs
•
Floating-point arithmetic
Min. 6 μs
Timers/counters and their retentivity 
S7 counters 
128
•
Retentive memory
Configurable
•
Default
from C0 to C7
•
Counting range
0 to 999
IEC Counters
Yes
•
Type
SFB
•
Number
unlimited (limited only by RAM size)
S7 timers
128
•
Retentive memory
Configurable
•
Default
Not retentive
•
Timer range
10 ms to 9990 s