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Entry type: FAQ Entry ID: 16619980, Entry date: 06/30/2008

How much hard drive space do messages and process values from SIMATIC WinCC V6.0 or PCS 7 V6.0 require?

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Process values:

  • A measured value in the "TagLogging Slow" archive requires 32 bytes of hard drive memory capacity
  • A measured value in the "TagLogging Fast" archive requires about 3 bytes of hard drive memory capacity (max. 40 bytes depending on compression)


Space requirements in the CS-database

  • A message in a language theoretically requires at least 198 Byte of hard disc space.
  • A message can theoretically use a maximum value of 5062 Byte.

    Each time this value is stored in a segment.

Hard disk space requirements in a RT-Data base

  • A message without accompaying values and comments requires at least 172 Byte of hard disc space.
  • A message with the maximum amount of accompanying values and comments requires 4012 Byte of hard disc space.

From WinCC V6.0 SP4 all data is held in the database in compressed form.
This means that the overall space required for storage is smaller and not easy to calculate. Therefore, the estimates set out above continue to apply. The information about the memory estimates listed above can be checked in the WinCC Information System under Information System > Release Notes > Notes about WinCC > WinCC Runtime > (Note about alarm logging: memory space required for messages).

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