Rockwell Automation FactoryTalk View Machine Edition Users Guide - Manual (Page 86)

F ACTORY T ALK V IEW M ACHINE E DITION U SER ’ S G UIDE
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HMI tags
In addition to direct referencing tags from data servers, FactoryTalk View allows you to
create tags with additional properties such as minimum and maximum values, scale, and
offset. These tags can reference values at an external data source, or store values in the
run-time computer’s memory. Tags you create in FactoryTalk View are called HMI tags.
The data source
The FactoryTalk View documentation uses the term data source as a generic term that
includes all possible sources of tag data, for both data server tags and HMI tags. The data
source can be memory or a device such as a programmable controller or an OPC server.
FactoryTalk View writes values to and reads values from the data source. The data source
is set up to exchange information (in the form of numeric or string values) between the
FactoryTalk View value table and the machine that your application is controlling.
Basic steps for using tags
To use tags, follow these basic steps:
1. If the tag does not already exist, create the tag.
To use a data server tag, you can use an existing tag in the processor (for example, a
programmable controller), or you can create a new one in the processor or OPC server.
For example, in a Logix5000 processor, you could create the tag using your RSLogix
5000, or Logix Designer programming software.
To use an HMI tag, you must first create it in the Tags editor. For details, see
Chapter 7.
2. Browse for, or type, the name of the tag anywhere you want to connect an object to
data at run time.
For example, to make a push button change a tag value when it is pressed, connect the
push button to a tag by typing the tag name in the Connections tab of the push button’s
Properties dialog box.
Browse for tags
If you don’t know the names of tags, you can browse for them. You can browse while
online and connected to a device, or you can browse for tags from an offline file, for
example a Logix5000 program file.
To browse for tags, use the Tag Browser. For details, see page 6-5.