Creating a Logger Tag

Before you can plot historical data or create a report for a given tag, you must ensure that the tag has an associated logger tag (the plotting of live data does not require an associated logger tag).

Analog and digital status tag types include built-in loggers. Do not add a second logger to these.  For others such as analog or digital input tags, the instructions below will assist you in adding and configuring a logger tag.

To add a new logger tag to your system:

1.   Click the Configure button. The Configuration Toolbox opens.

2.   Click the Tag Browser button. The Tag Browser opens.

3.   Select Logger from the Tag Browser's Types drop-down list.

4.   Ensure that All is selected in the Areas drop-down list, and that * is entered in the Search field.

Any logger tags that have already been added to your system are displayed. (If no loggers have been added to your system yet, nothing will be displayed in the Tag Browser's list of available tags.)

5.   Click the New button. A new tag properties folder for a logger tag will open.

6.   Enter a name for this logger tag in the Name field.

Remember to conform to your application's tag naming convention. (Typically, logger tags are named the same as the basic I/O tags, but then prefixed or post-fixed with LOG – e.g. AI10_1_LOG, or LOG_120-A-5).

7.   Enter the area for this logger tag in the Area field.

This should be the same as the area of the tag the logger is to be linked to.

8.   Enter a description for this logger tag in the Description field.

This description will assist you in determining the purpose of this logger, so make it as detailed as you wish.

9.   Click the Conditions tab.

10. Click the … button to the right of the Log Data From field.

The Tag Browser opens and displays only the numeric tags in your application (as numeric tags are the only tags that can have loggers configured to record their data).

11. Select the name of the tag for which you wish this logger to record data to disk in the Tag Browser.

12. Click the Select button.

The tag you selected is now referenced in the Log Data From field.

13. [optional] Select the Log on Change as Well as Time checkbox.

If you wish this logger to record the data for the selected numeric tag each time its value changes, in addition to the logging schedule you will configure using the Log Rate tab.

14. Click the Log Rate tab.

15. Enter the number of seconds you wish VTS to wait between logs of the data for the numeric tag associated with this logger tag in the Interval (Seconds) field.

The lower that this value is set, the more frequently data will be logged for the associated numeric tag.

16. Decide whether you want to set a limit on the number of records that will be saved in the .DAT file

•   If there is to be a limit, enter the total number of records you wish to be saved in the Number of Records in File field

•   If there is to be no limit other than disk capacity, click the Maximum Possible Records checkbox to allow VTS to store the maximum number of records (as calculated by VTS).

If you chose to set a limit, then the oldest records in the file will be overwritten with new ones once the file is filled to its designated capacity.   You may also check the Create File Full Size checkbox to have a full-size data file for this logger tag created immediately (rather than the file growing as records are added). This will help to prevent disk fragmentation.

17. Enter the total number of records you wish VTS to store in RAM prior to writing the data to the data file associated with the numeric tag related to this logger tag in the Number of Records in RAM field.

If the Number of Records in RAM field is set to 0, data is written to disk each time a new data sample is logged. If Number of Records in RAM is set to a value greater than 0, the specified number of records will be saved in RAM before being written to disk. Do not set this value too high, or you may risk losing considerable data in the event that a power failure should occur.

18. Click the OK button to save the new logger tag.

The Tag Browser reopens, and the new logger tag is shown in the list of tags.