csmstr - Omega Engineering

CONFIGURING DATA TAGS
CREATING TAGS
• Tags allow you to avoid re-entering the same information again and again. When
you create a tag, you specify how the tag is to be displayed. In the case of an
integer tag, this means you tell Crimson how many decimal places are to be
used, and what units, if any, are to be appended to the value. When you place a
tag on a display page, Crimson knows how to format it without you having to do
anything further. Similarly, if you decide to change the formatting, and perhaps
switch from one set of units to another, you can do this in one place, without
having to edit each display page in turn.
• On Masters configured to have a color virtual HMI, tags are used as the basis for
color animation. The various colors that are defined for a tag can be used to
specify the way in which other animation primitives will be displayed. Without
tags, you will have no way of changing the color of anything other than textbased
data fields.
• Tags are the key to implementing slave protocols. Crimson treats these protocols
as mechanisms for exposing data items within the Master. This allows the same
data to be accessed via multiple ports, so that, for example, a machine setting
could be changed by both a local SCADA package, and a similar package
working over Ethernet from a remote site. Without tags, there would be nothing
to expose, and this mechanism could not be implemented!
• Tags are used within Crimson to implement many advanced features. If you
want to use functionality such as alarms, triggers, data logging or the web server,
you will have to use tags, period. The formatting data from the tag definition is
typically required by all these features, so tags are mandatory for their operation.
In other words, tags will automate many tasks during programming, saving you time. Even if
you decide not to use tags, many of the subsequent chapters of this manual refer to concepts
discussed in this chapter. You should thus read it thoroughly before proceeding.
CREATING TAGS
To create a tag, either click on one of the buttons displayed when the Tags icon is selected in
the left-hand pane of the Data Tags window, or use the new tag buttons on the toolbar. Either
way, a new tag will be added to the tag list. To edit the tag’s name, select the tag in the
left-hand pane, and type in the new name.
Tag names must conform to the following rules…
• Tag names may not contain spaces or punctuation.
• Tag names must start with a letter of the alphabet or an underscore.
• Subsequent characters must be digits, letters or underscores.
• Names must not exceed 24 characters in length.
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