Rockwell Automation 2706-P42_P43_P44_P72_P74_P92_P94 InView Marquee Message Display User Manual - Manual (Page 119)

1 Publication 2706-UM016D-EN-P - March 2006
Chapter
5
InView Control and
InView Control API
Introduction The purpose of this chapter is to describe the API for the InView
control. The chapter is divided into two sections. The first section is a
quick overview on how to use the control. It highlights the basic steps
needed to get the control up and running. The second section is a
detailed reference of the properties and methods available in the
control. Each property and method is listed in a table with a brief
description and a link to a more complete description.
Quick Overview The InView control is designed primarily for use with the InView
messaging software. The InView messaging software is used to create
and download messages to the display, and the InView control is used
to trigger the messages and update variables within those messages.
Assuming that the InView messaging software has already been used
to load the display with messages, there are five basic steps to using
the control to trigger a message:
1. Add the control to your project. It appears as InView control
under Project|Components… in Visual Basic.
2. Call the Initialize method to open a connection to the display.
3. Set the heartbeat property to 2 to disable the display’s heartbeat
requirement.
4. Call the AddMessage method to trigger a message on the
display.
5. Call the UpdateVariable method to change the value of a
variable.
Following is a snapshot of a Visual Basic form and its associated code
that illustrates these five steps. This code assumes that the display
contains a message in slot number 1, and that the message contains
variable 0 within its body. It also uses the controls default
communications settings of serial on COM1 to connect with the
display.
Private Sub Command1_Click()