2 Visual Components Manuals

4.2.1.8 CAN − Step 8: Defining INC/DEC Keys
Introduction to Visual Components 2.3
In order to manipulate the "LedCtrl" PV which has direct influence on the F1 LED blink status, we define F2 as
an increment key which raises the "LedCtrl" variable by one value per keystroke (maximum 3). F3 will be set up
as a decrement key. It will reduce the PV by one value per keystroke (minimum 0).
First, the F2 function key must be set with the increment/decrement function. For this, right click on the F2 key in
the Key window (but not within the LED). Select Increment/Decrement from the shortcut menu.
A dialog box appears which provides a more exact definition of all necessary function parameters.
The Data Point area under the Parameter tab determines which PV should be manipulated. Select the 'LedCtrl'
PV from the variable dialog box which appears after you have clicked on the Assign... button.
Under the Function tab, activate the Use Limits option to define the maximum as 3. This is because an LED can
only have 4 different states (0−3). The Increment rate is defined as 1. We confirm our selections with OK, and
232 4.2.1.8 CAN − Step 8: Defining INC/DEC Keys