Siemens SIMATIC S7-300 Series Reference Manual page 44

CPUs
Technical Specifications of the CPU 312 IFM
CPU and Product Version
MLFB 6ES7 312-5AC02-0AB0
S
Hardware version 01
S
Firmware version V 1.1.0
S
Matching programming STEP 7 V 5.0;
Service Pack 03
package
Memory
Work memory
S
integral 6 KB
S
Expandable no
Load memory
S
integral 20 KB RAM
20 KB EEPROM
S
Expandable FEPROM no
S
Expandable RAM no
Backup Yes
S
With battery no
S
Without battery 72 bytes retentive
Configurable
(data, flags, timers)
Processing times
Processing times for
S
0.6 ms minimum
Bit instructions
S
2 ms minimum
Word instructions
S
3 ms minimum
Double integer math
S
60 ms minimum
Floating-point math
instructions
Timers/Counters and their retentive characteristics
S7 counters 32
S
Adjustable retentivity from C 0 to C 31
S
Preset from C 0 to C 7
S
Counting range 1 to 999
IEC Counters Yes
S
Type SFBs
S7 timers 64
S
Adjustable retentivity No
S
Timing range 10 ms to 9990 s
IEC Timers Yes
S
SFBs
Type
1-28
Data areas and their retentive characteristics
Retentive data area as a
whole (inc. flags, timers,
counters)
Bit memories
S
Adjustable retentivity
S
Preset
Clock memories
Data blocks
S
Size
S
Adjustable retentivity
S
Preset
Local data (non-alterable)
S
Per priority class
Blocks
OBs
S
Size
Nesting depth
S
Per priority class
S
additional levels within
an error OB
FBs
S
Size
FCs
S
Size
Address areas (I/O)
Peripheral address area
S
Digital
– integrated
S
Analog
Process image (cannot be
customized)
Digital channels
Analog channels
PLC S7-300, CPU Specifications CPU 312 IFM to CPU 318-2 DP
max. 1 DB, 72 data bytes
1024
MB 0 to MB 71
MB 0 to MB 15
8 (1 memory byte)
max. 63 (DB 0 reserved)
max. 6 KB
max. 1 DB, 72 bytes
No retentivity
max. 512 bytes
256 bytes
See Instruction List
max. 6 KB
8
None
max. 32;
max. 6 KB
max. 32;
max. 6 KB
0 to 31/0 to 31
124,125 E/124 A
256 to 383/256 to 383
32 bytes+4 bytes
integrated/ 32 bytes+4
bytes integrated
256+10 integrated/256+6
integrated
64/32
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