Dynacard Reference Tag

The Dynacard Reference tag allows you to store a particular data set from a Dynacard Input tag as a reference. For example, if you take a known good stroke as a reference, you can display that on the Dynagraph next to the current strokes on an ongoing basis. This allows you to see when the two Dynacard data sets are starting to diverge from one another. References are saved from the Dynacard Graph screen (Dynacard Display).

Related information:

Best Practices for Tags

Dynacard Reference properties ID tab

The ID tab of every tag includes the same common elements: Name, Area, Description, and Help ID.

Name:

Uniquely identifies each tag in the application. If the tag is a child of another, the parent names will be displayed in a separate area before the name field.

You may right-click on the tag's name to add or remove a conditional start expression.

Area

The area field is used to group similar tags together. By defining an area, you make it possible to:

Filter for particular tag groups when searching in the tag browser
Link dial-out alarm rosters to Alarm tags having a particular area
Limit the number of tags loaded upon startup.
Filter the alarm display to show only certain areas.
Filter tag selection by area when building reports

When working with Parent-Child tag structures, the area property of all child tags will automatically match the configured area of a parent. Naturally, you can change any tag's area as required. In the case of a child tag, the field background will turn yellow to indicate that you have applied an override. (Orange in the case of user-defined types. Refer to Configuration Field Colors)

To use the area field effectively, you might consider setting the same Area for each I/O driver and its related I/O tags to group all the tags representing the equipment processes installed at each I/O device. You might also consider naming the Area property for the physical location of the tag (i.e. a station or name of a landmark near the location of the I/O device). For serial port or Roster tags, you might configure the Area property according to the purpose of each tag, such as System or Communications.

You may define as many areas as you wish and you may leave the area blank for some tags (note that for Modem tags that are to be used with the Alarm Notification System, it is actually required that the area field be left blank).

To define a new area, type the name in the field. It will immediately be added. To use an existing area, use the drop-down list feature. Re-typing an existing area name is not recommended since a typo or misspelling will result in a second area being created.

There is no tool to remove an area name from VTScada since such a tool is unnecessary. An area definition will exist as long as any tag uses it and will stop existing when no tag uses it (following the next re-start).

Description

Tag names tend to be brief. The description field provides a way to give each tag a human-friendly note describing its purpose. While not mandatory, the description is highly recommended.

Tag descriptions are displayed in the tag browser, in the list of tags to be selected for a report and also on-screen when the operator holds the pointer over the tag’s widget. For installations that use the Alarm Notification System, the description will be spoken when identifying the tag that caused the alarm.

The description field will store up to 65,500 characters, but this will exceed the practical limits of what can be displayed on-screen.

This note is relevant only to those with a multilingual user interface:
When editing any textual parameter (description, area, engineering units...) always work in the phrase editor. Any changes made directly to the textual parameter will result in a new phrase being created rather than the existing phrase being changed.
In a unilingual application this makes no difference, but in a multilingual application it is regarded as poor practice.

Help Search Key

Used only by those who have created their own CHM-format context sensitive help files to accompany their application. Refer to Custom Help Files

Dynacard Reference properties Data Sets tab

Number of Data Sets to Display

Choose how many to display, up to a maximum of 10.

Data Set X Color

Choose the color to be used by the matching data set.

Dynacard Reference properties Historian tab

Historian

If an Historian tag is selected, this tag's run-time values will be saved for use in reports and the Historical Data Viewer. Historian configuration and advanced logging options are described in the discussion of the Historian Tags.

If your goal is to disable logging, set the Enable parameter (below) to 0 rather than deleting the Historian parameter.

There are consequences if you change the selected Historian tag after you have begun collecting data. If you switch to a new Historian (perhaps for organizational or load sharing purposes), the data collected for this tag by the previous Historian will become inaccessible. Historian selection and configuration should be done during the project design stage.