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Logging Page (Shared Variable Properties Dialog Box)

LabVIEW 2013 Datalogging and Supervisory Control Module Help

Edition Date: June 2013

Part Number: 371618J-01

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Requires: DSC Module

In the Shared Variable Properties dialog box, select Logging to display this page.

Use this page to configure logging for a shared variable.

Note  You can enable logging for network-published shared variables only.

This page can include the following components:

  • Enable Logging—Specifies whether LabVIEW logs data and events for the shared variable.
  • Log Alarms & Events—Specifies whether LabVIEW logs alarm and event data for the shared variable.
  • Log Data—Specifies whether LabVIEW logs data for the shared variable.
  • Value Resolution—Sets the resolution, in engineering units, for logging the shared variable value in the Citadel historical database. LabVIEW writes shared variables to the Citadel historical database in compressed format with the specified resolution. The default value is 0.01.

    Enter a value of 0.0 to write the exact value of the shared variable to the Citadel historical database. Logging the exact value requires more time and disk space. This option is available only for shared variables with a floating-point data type.
  • Value Deadband—Sets the deadband percentage for logging shared variables in the Citadel historical database. LabVIEW logs a new shared variable value only if the difference between the new value and the previous logged value is greater than or equal to the deadband percentage of the engineering scale range. The engineering scale range is 100 by default. The default value of Value Deadband is 1%.

    Enter a value of 0 to log every value written to the shared variable. Use this option to improve the performance of an application by limiting unnecessary data logging. This option is available only for shared variables with a floating-point data type.
  • Logging Format—Specifies the format in which LabVIEW logs strings in the Citadel historical database. This option is available only for shared variables with a data type of String.
    • String—Logs strings in LabVIEW string format.
    • DSC 7.1 Text—Logs strings in Unicode format.
    • DSC 7.1 Blob—Logs strings in raw binary data format.
    Select DSC 7.1 Text or DSC 7.1 Blob for compatibility with the LabVIEW Datalogging and Supervisory Control (DSC) Module 7.1. Otherwise, select String.
Note   LabVIEW stores logged data in the database you specify on the Citadel page or Relational Database page of the DSC Settings: Database page of the Project Library Properties dialog box.

 

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