Dialog Box ‘Trend storage’

Function: This dialog box includes the configuration for buffering the trend data of a trend recording.

Call: Trend Storage button in the editor of a trend recording.

Maximum number of variables Maximum number of trend variables that can be managed in the database. If you increase this value afterwards, then will CODESYS perform a download and reconfigure the database.
Store every N milliseconds

Time interval (in ms) when the CmpTraceMgr runtime system component buffers the recorded data before storing it persistently in the database. The application calculates internally the number of task cycles from the time interval. The duration of a task cycle is defined in the task configuration.

A high value results in better runtime performance. The disadvantage is the increased risk of losing data if the controller crashes or shuts down. A low value reduces this risk. The disadvantage is the slower control over a trend visualization with large amounts of data.
Limit

7f862ee177e85b2cc0a8640e00b38a06_1c4140bc6335e686c0a8640e00b47802 : Limit the recording

  • No Limit: Unlimited number of data records (not recommended)

  • Maximum number of records: Maximum number of data records that are stored in the database. A data record consists of time stamp and the values of the trend variables at this time.

  • Maximum storage size: Maximum size of the trend storage. The application calculates internally the number of data records.

    Clicking the “down” symbol ( 7f862ee177e85b2cc0a8640e00b38a06_379d3b8945773148c0a8640e0139d9cb ) of the drop-down list will set the units to kilobytes (KB), megabytes (MB), or gigabytes (GB).

See also