Rockwell Automation GMLC Reference Manual - Manual (Page 494)

Publication GMLC-5.2 - November 1999
Chapter
24
User Variables and Constants
The Expression Builder lets you use defined user variables, constants, and
local DH-485 variables as elements in expressions. Select User Constants,
User Variables, or DH-485 in the Tag Explorer. Then select the desired
variable or constant in the Tag Window.
Before a user variable or constant becomes available for use in an
expression, you must first define it. If the Tag Window’s scrolling list is
empty, no variables or constants have been defined.
All user variables and constants are strings of standard ASCII characters
that can be entered directly from the keyboard into an expression.
Inputs and Outputs
You can also include defined discrete inputs, discrete input groups,
discrete outputs, and discrete output groups as elements in your
expression.
In the Tag Explorer, under the desired communications type Flex I/O,
(AxisLink I/O, RIO or SLC) select the desired input or output. Then, in
the Tag Window, scroll the list until the desired item appears. If the list is
empty, no items have been defined for your diagram.
To define a new item:
1. Place the pointing arrow in the Tag Window.
2. Click the right mouse button. A pop-up menu appears.
3. Select New. A definition dialog box for the selected item appears.
4. Define the item by completing the dialog box.
5. Select OK.