12.17 Modifying a Pen Group

Earlier in this lesson, you learned how to add a new pen group to your application. In the last exercise, you added the new notebook tag to the pen legend using the Tag Selector dialog. You will now modify the pen group by adding the new notebook tag to it.

1.  Click the Tag Selector button.

The Tag Selector dialog will open, with the pens belonging to the Pump Status Tank Level pen group and the OpNotes01 notebook tag displayed in the Selected Tags/Queries for Plotting list.

2.  Click the Save Group button. The Save Group dialog will open and display the name of the pen group you are editing.

3.  Click the OK button. You are returned to the Tag Selector.

4.  Click the Plot button to return to the graph on the Historical Data Viewer page.

You can now test the pen group to ensure that the notebook tag has been saved with the analog and digital tags. To do so, expand the pen group selector drop-down list, and select Empty to first clear the graph of all pens. Then select the Pump Status Tank Level pen group from the pen group selector drop-down list. The AI20_1, DI10_1, and OpNotes01 tags should now appear in the pen legend.

 

Skills Achieved in Lesson 12

By completing Lesson 12, you learned the following:

•      VTS automatically generates a Historical Data Viewer page when you create a new standard application.

•      The Historical Data Viewer page is a graph whose X-axis displays the time/date of the data being displayed, and whose Y-axis displays the scale range for each tag being represented on the graph.

•      The Historical Data Viewer page enables you to configure "pens" to plot tag data on the graph. Each pen plots the data for its associated tag according to the time duration you've specified and according to the data value range for the selected tag.

•      Each pen is displayed in a unique color and is referenced in the "pen legend" to the left of the Historical Data Viewer page. The pen legend enables you to identify which pen is plotting which tag's data. Additionally, you can change the amount of information that is displayed for each pen by right-clicking the pen's entry in the pen legend, selecting "Properties", and modifying the pen properties dialog.

•      The Historical Data Viewer page enables you to perform a wide variety of functions to manipulate plotted data. You can export the data for the tag associated with any pen; zoom in or out on data to view greater or lesser time periods, or greater or lesser scale ranges; shift analog pen plots around on the page; and save and retrieve frequently used groups of pens.

•      "Logger" refers to a specific tag type. Loggers are special tags that can be configured to record the value for any of the standard tag types that have numeric values. Logger tags record the data values to a data file and generate a log file to keep track of the data files. Both the data file (".DAT" extension) and the log file (".LOG" extension) are named based on the name of the tag whose data is being monitored.

•      Only one logger tag can be directly associated with a standard tag type. If you wish to log tag data at different log rates for the same tag, you may do so using calculation tags. Please refer to the VTS Developer's Guide for information on calculation tags.