Assigning data point elements to archives

Data points can be assigned to archives only when the archives have been created.

The panel for the _archive config contains a list of the created and configured archives. By default, five archives have been created and can be selected from the combo box. The Configure... button opens the tab (of the History DB) that allows you to create and configure archives.

Figure 1. "Archiving" panel
  1. Create the data point.
  2. Append the config _archive.
  3. Open the combo box.
  4. Select an archive. The archive is assigned to your data point by clicking on Apply or OK.
  5. You can also smooth your original values (see config _archive - Smoothing modes).

When changing an archived DP element assignment from one archive to another archive and back again (e.g.A1 -> A2 -> A1 -> A2), consider to perform at least one archive record change of the archive that was assigned at first (A1). Assign a DP element to the archive A1 first after this archive record change. This is necessary since the archives only contain DP element assignments per archive record.

Creating a config _archive in the PARA module or setting the _archive.._type <> 0 in a CTRL script does not automatically activate the archiving. You have to enable the archiving in the archive config via the check box "Active".

The source time of a data point value should not be older than the start time of the archive. This means that no values can be stored in an archive before the initial start time of an archive. In such cases, the source time is set to the archive start time and the TIMEINVALID bit is set. When a DPE is assigned to an archive, an entry with the current value of the DPE in the archive and the TIMEINVALID bit are set.

Values with a time stamp from the past are written into the corresponding "old" archive set (only as long as there is no present time stamp for this DPE). This can cause problems especially in connection with the compression and the free places in an archive.