Rockwell Automation FactoryTalk View Site Edition Users Guide - Manual (Page 485)

17 • C REATING GRAPHIC OBJECTS
17–43
•
•
•
• •
17
•
Pla
ceho
lde
r
The operator presses the keys to scroll up or down the list, or to make selections from the
list. The keys can be set up to work with the control list selector that has focus, or with a
specific control list selector.
For more information about keys, see “Using key objects to simulate keyboard functions”
on page 17-32.
Setting the Value tag
At run time, the Value tag changes:
 When the operator selects the next item in the list.
 When the operator presses the Enter key, if the control list selector requires that a
selection be confirmed using the Enter key.
 When another process changes the tag’s value in the network device.
For example, a control list selector is used to change a tag’s value. If the tag’s value is
zero, when the operator selects the next state, the tag’s value changes to the value for
the next state, for example 1.
If another process changes the tag’s value to 2, the next time the operator selects the
next state, the tag’s value changes to 3.
Using Enter key handshaking to ensure the current value is read
When the operator presses the control list selector’s Enter key, the highlighted state’s
value is written to the network device.
Use Enter key handshaking to hold the current value of the tag at the network device for a
specified period, to ensure it is read before the control list selector overwrites it with a
new value.
Before Enter key handshaking completes for an object, the operator can provide input to
other objects in the graphic display. However, if the operator presses the Enter key for an
object before its handshake is completed, an error is sent to the Diagnostics log file.
If the graphic display is closed, the Enter tag is reset to 0, and any handshake timing is
also reset.
Creating control list selectors
Use the Control List Selector tool to create a list that shows multiple options, which an
operator can cycle through consecutively. The control list selector shows the current state
of a process or operation by highlighting the state.
Each time the operator presses a key, the control list selector’s highlight changes position,
and the Value tag changes to the value for the next state.
Control List
Selector tool