Logging Historical Data (DSC Module)

To log shared variable data from the Shared Variable Engine to the Citadel database, you need to enable logging for shared variables and processes.

Complete the following steps to enable logging for processes by using the NI Distributed System Manager.

  1. In the system tree pane, right-click the localhost system and select Add Process to display the Add/Edit Process dialog box.
    Note��You also can enable logging for processes by using the Add/Edit Process dialog box. Right-click a process and select Edit Process to display the Add/Edit Process dialog box.
  2. Enter the process name for the new process in the Process name text box.
  3. Place a checkmark in the Enable Data Logging checkbox to enable data logging.
  4. Enter the name of the computer to which you want to log data in the Log to computer text box. LabVIEW logs data to the local computer if you leave the text box blank. If you want to log data to a remote computer, ensure you have installed the LabVIEW Datalogging and Supervisory Control (DSC) Module or the DSC Module Run-Time System on that remote computer.
    Note��Refer to the National Instruments Web site for information about the DSC Module Run-Time System.
  5. Enter the name of the database to which you want to log data in the Database name text box.
  6. Enter the location of the database to which you want to log data in the Database path text box. If you log data to directories created in a secure file system, such as NTFS, you must grant Change or Full Control permissions for the current user, the SYSTEM account, and the NETWORK SERVICE account to access the directory. If you do not grant these accounts appropriate access to the database directory, the Citadel service cannot create and modify the database files it uses to store historical data and alarms.
    Note�� (Windows 7/Vista) The Citadel service does not have access to a specific user folder, for example, C:\Users\lvadmin\. Therefore, the Citadel service is unable to create or modify databases in this folder.
  7. Specify the length of time you want data to be available in the database in the Data Lifespan options.
  8. (Optional) Place a checkmark in the Enable Alarms and Events Logging check box to log alarms and events.
  9. Place a checkmark in the Use the same database for alarms and events checkbox to use the same database you set up for data logging.
  10. Click the OK button to close the dialog box.