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Entry type: Product note, Entry ID: 35354298, Entry date: 05/19/2009

Innovated CPU 312, CPU 314, CPU 315-2 DP and CPU 315F-2 DP Released for Delivery

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The innovated S7-300 CPUs 312, 314, 315-2 DP and 315F-2 DP with firmware V3.0 have been released for delivery under new order no.'s..
The new S7-300 CPUs are spare part compatible with their predecessor versions.


Product information
Compatibility and necessary components
Ordering information
Further information

Product information
Basic data:

CPU Designation CPU 312 CPU 314 CPU 315-2 DP CPU 315F-2 DP
Memory 32 KByte / 10 k statements / 32 KByte retentive 128 KByte / 42 k statements / 64 KByte retentive 256 KByte / 85 k statements / 128 KByte retentive 384 KByte / 128 k statements / 128 KByte retentive
Bit performance 0.10 µs 0.06 µs 0.05 µs 0.05 µs
Word performance 0.24 µs 0.12 µs 0.09 µs 0.09 µs
Fixed-point arithmetic 0.32 µs 0.16 µs 0.12 µs 0.12 µs
Floating-point arithmetic 1.10 µs 0.59 µs 0.45 µs 0.45 µs
Process I/O image
  • Adjustable max.
  • Default








Interfaces X1: MPI interface X1: MPI interface X1: MPI interface
X2: DP interface
X1: MPI interface
X2: DP interface
Dimensions CPU WxHxD (mm) 40 x 125 x 130 40 x 125 x 130 40 x 125 x 130 40 x 125 x 130


  • Performance increase:
    • Increase of the bit performance by a factor of up to 2
  • Memory increase
    • CPU 314 from 96 KByte to 128 KByte
    • CPU 315-2 DP from 128 KByte to 256 KByte
    • CPU 315F-2 DP from 192 KByte to 384 KByte
  • Simultaneous monitoring of 2 blocks
  • Harmonization of the technical data
  • Increase of the process I/O image
  • Isochronous mode on PROFIBUS for CPU 315(F)-2 DP
  • Data record routing for 315(F)-2 DP

The performance of the innovated S7-300 CPUs has been significantly increased compared to the existing CPUs 312, 314 and 315(F)-2 DP; e.g the user programs on the innovated CPUs are processed faster by factor of at least 2, in some cases even more. Processing times of down to 50 ns are achieved for bit operations and 90 ns for word operations. The performance of fixed-point and floating-point arithmetic operations has also been increased significantly.

Simultaneous monitoring of 2 blocks
Firmware version V3.0 of the S7-300 CPUs permits simultaneous monitoring of 2 blocks. The user has the option of simultaneously monitoring two blocks on one PG or PC, or one block each on two PGs or PCs. Furthermore, the no. of visible program lines in Block Status has been increased; STEP 7 V5.4 SP5 is manadory for this feature.

Harmonization of the technical data
The technical data of the S7-300 CPUs have been harmonized. The following quantity frameworks of S7-300 CPUs have been aligned or increased:

  • Same block number band (FC, FB, DB) for all S7-300 CPUs. Block number bands will increase to S7-400 level.
    • Block number band for FCs / FBs:    0 to 7 999
    • Block number band for DBs:            1 to 16 000

    Please note that the overall no. of FCs, FBs and DBs remains unchanged

  • Same local data size
    • max. 32 KB per execution level
    • max. 2 KB per block
  • Same nesting depth per priority class:    16
  • Same block size for all S7-300 CPUs above CPU 312:    64 KB
    CPU 312:    32 KB
  • Uniform for all S7-300 CPUs: 300 simultaneously active Alarm_S blocks
  • Same no. of time-delay interrupt OBs: OB20 and OB21
  • Same no. of time interrupt OBs: OB32, OB33, OB34 and OB35
  • Same no. of  global data circuits with global data communication:    8
  • No. of breakpoints increased from 2 to 4
  • 256 Byte of flags for CPU 312
  • 256 S7 timers / S7 counters for CPU 312
  • Diagnostic buffer:
    • Size of the diagnostic buffer: in general 500 entries, of which the 100 latest entries are retentive
    • The no. of displayed diagnostic buffer entries in RUN of the
      CPU can be configured between 10 and 499. The default is 10 entries

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Compatibility and necessary components

The innovated S7-300 CPUs replace the predecessor versions; they are spare part compatible.

The previous 312, 314, 315(F)-2 DP CPUs will remain available for ordering for approx. one more year in parallel with the new CPUs. After that only CPUs with firmware V3.0 or higher will be shipped.
Firmware V3.0 can only execute on the new S7-300 CPUs and cannot be installed on the predecessor hardware.

* Note:
When you use temporary variables please note that they are only valid for the relevant software block; they are also available to other nested blocks as previous local data.
In particular it is not assured that when a block is exited and called again the temporary variables regain the values they had when the previous call was closed.
By definition, temporary variables are at first unassigned when a software block is called and must be initialled when the block is used for the first time.

* Amended Aug. 13. 2009



Order No.

STEP7 & HSP File
CPU 312 6ES7312-1AE14-0AB0 STEP 7 V5.2 + SP1 with HSP 176, or higher
CPU 314 6ES7314-1AG14-0AB0 STEP 7 V5.2 + SP1 with HSP 175, or higher
CPU 315-2 DP 6ES7315-2AH14-0AB0 STEP 7 V5.2 + SP1 with HSP 177, or higher
CPU 315F-2 DP 6ES7315-6FF04-0AB0 STEP 7 V5.2 + SP1 with HSP 177, or higher

In the case of a spare part replacement:
If you replace a CPU (e.g. 6ES7314-1AG13-0AB0) against a compatible follow-up type (in this case ES7314-1AG14-0AB0) the STEP 7 project need not be changed. It is also not necessary to upgrade the STEP 7 software version.

In Hardware Config  Actual Hardware
6ES7314-1AG13-0AB0 6ES7314-1AG14-0AB0

When you use compatible follow-up types you can always work in the STEP 7 project with the order no. of the predecessor types.

Configuration with older software versions:
If the new functions are not required, the new module can be configured in STEP 7 as the predecessor with the latter's scope of functions. The larger work memory is nevertheless available.

In Hardware Config  Actual Hardware
6ES7314-1AG13-0AB0 6ES7314-1AG14-0AB0

It is also not necessary to upgrade the STEP 7 software version in this case.

Configuration with new order no.:
If the module is to be configured under its new order no., a Hardware Support Package (HSP files) must be installed in STEP7. Using this HSP file the new CPU can also be configured with older STEP7 versions (not older than V5.2 SP1).
Information on how to download and install the HSP file is available under entry ID 17581199. Working on the CPUs with older STEP 7 versions than V5.2 SP1 is not possible.

Distributed Safety
In addition to STEP 7, the CPU 315F-2 DP requires the Distributed Safety V5.4 software.

SIMATIC Micro Memory Card (required for CPU operation)
The CPUs make use of a SIMATIC Micro Memory Card. It is used as plug-in loading memory but can also store compressed STEP7 projects incl. comments and symbolics (please note project and card sizes).
The SIMATIC Micro Memory Card can also be used to create data blocks via SFCs and store or read data.

The following types can be used:


Order No.

SIMATIC Micro Memory Card 64 kB 6ES7953-8LF20-0AA0
SIMATIC Micro Memory Card 128 kB 6ES7953-8LG11-0AA0
SIMATIC Micro Memory Card 512 kB 6ES7953-8LJ20-0AA0
SIMATIC Micro Memory Card 2 MB 6ES7953-8LL20-0AA0
SIMATIC Micro Memory Card 4 MB 6ES7953-8LM20-0AA0
SIMATIC Micro Memory Card 8 MB 6ES7953-8LP20-0AA0

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Ordering information
The list price of the CPUs remains unchanged.

Designation Order No. of previous CPU Order No. of new CPU
CPU 312 6ES7312-1AE13-0AB0 6ES7312-1AE14-0AB0
CPU 314 6ES7314-1AG13-0AB0 6ES7314-1AG14-0AB0
CPU 315-2 DP 6ES7315-2AG10-0AB0 6ES7315-2AH14-0AB0
CPU 315F-2 DP 6ES7315-6FF01-0AB0 6ES7315-6FF04-0AB0

Further information

More information is available from:

Internet www.siemens.de/SIMATIC-S7-300

User manuals:

Order No. Product Description Entry ID
6ES7398-8FA10-8AA0 (German)

for other langages:


S7-300, CPU 31xC and CPU 31x: Installation Manual, German 13008499
CPU 31xC and CPU 31x, Technical Data Manual, German 12996906
S7-300, Module Reference Data, German 8859629
S7-300, CPU 31xC Technological Functions 12429336
S7-300 Getting Started Collection, German 15390497
PROFINET IO Getting Started Collection, German 19290251
List of Operations SIMATIC S7-300, 
CPU 31yC, CPU 31x, IM 151-7 CPU, BM 147-1 CPU, BM 147-2 CPU, German
List of Operations SIMATIC S7-300
CPU 312, CPU 314, CPU315-2DP for Firmware >= V3.0, German
PROFINET System Description 19292127
6ES7998-8XC01-8YE0 SIMATIC Manual Collection CD, in 5 languages  
6ES7998-8XC01-8YE2 SIMATIC Manual Collection CD, in 5 languages, update service for 1 year  

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