Siemens SIMATIC NET CP 343-1 Manuel d'utilisateur télécharger pdf (Page 43)

5 Performance Data / Operation

B−43

CP 343-1 Advancedfor Industrial Ethernet / Manual Part B

Release 06/2008

C79000-G8976-C202-04

Meaning of the memory areas

On the CP 343-1 Advanced, the file system is divided into 2 areas:

S Flash area in the C-PLUG (non-volatile memory):

The flash area allows data to be stored and retained if there is a power down.

Since the number of times it is possible to write to this area is restricted, you

should avoid repetitive write operations to this area, when such operations are

necessary, write to RAM.

Notice

The flash area of the file system allows a limited number of write cycles

(approximately 100 000). You should therefore avoid writing data cyclically.

If you write temporary data often, you should switch to the RAM file system

located in the /ram subfolder. The files of the RAM file system (/ram) are lost if

there is power down.

S RAM area (/ram volatile memory):

In contrast to the flash area, the RAM can be written to and read from any

number of times. The data in the RAM are retained as long as the CP is

supplied with power.

The RAM is intended to store data that change during operation and need to be

recorded (data recording services). The RAM is also suitable for temporary

storage.

The RAM is located in the file system below the “/ram” folder. All files and

folders below this folder are lost when there is a power down.

Please remember the following restrictions:

Table 5-11

Characteristic

Explanation / values

File names The length of the file names is limited. Up to 64 characters are

permitted for the file name, up to 256 characters for the path.

It is possible to make the file name case-sensitive in the “Options” tab

of the CP properties dialog.

File size The file size is limited to a maximum of 8 MB.

Memory area for the file system − Flash area (non-volatile memory)

28 MB

− RAM area (volatile memory)

30 MB

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Siemens SIMATIC NET CP 343-1 Manuel d'utilisateur Page 43