Manual-9
sliders, buttons, indicators and other graphical screen entities.
The objects have properties such as slider position and slider
range and on or off for buttons and indicators, etc. Once the
screen objects are chosen and placed, ActiveX controls can
then be used to link to the object’s properties to other
ActiveX controls. Thus, allowing linking a slider to the
ActiveX control for a level control so moving the level
control graphic subsequently varies the audio level.
Implementing ActiveX controls. An example might help
clear this up. A few assumptions are that a computer is used
to control an audio system over a 10Base-T Ethernet network
and that something on the computer’s screen controls some
function of the system. The basic idea is to place controls on
the computer screen and link them, using ActiveX, to a
parameter in the system. What’s important here is that only
the controls required by the computer’s end user need be
displayed. Additionally, more detailed interfaces (hidden or
password-protected web pages) can then be created to provide
any level of system parameter access desirable—from
complete system control, to a lone system power button or
anything in-between. No longer are systems limited to the
number of security levels provided by vendor’s software, nor
are you limited to controlling a single system parameter per
screen control. For example, you can link multiple ActiveX
controls to a single screen object, thus adjusting EQ level
simultaneously with master level control and limiter thresh-
old. You can also program actions when certain events occur,
such as triggering audio playback or turning a system off at a
certain time or adjusting delay time as the temperature
changes.
Microsoft FrontPage 2000 ActiveX example. Many use
Microsoft’s FrontPage 2000 to create user interface web
pages for computer-controlled systems. These web pages may
or may not be accessible over the Internet. The examples
found on Rane’s web site will review the basic FrontPage
2000 procedures to link screen controls to ActiveX controls.
A second example illustrates how to use Events, such as
clipping, to program a hands-off script to turn a level down.
Once you master these two concepts, using FrontPage with
ActiveX provides literally an infinite number of programming
possibilities. More information about the Via 10’s I/O port
ActiveX controls and the ActiveX controls for Rane’s RW
232 devices is found in the sections below.
Via 10 ActiveX Example. The short version of this
procedure is: insert a Via 10 ActiveX control in your web
page, set the control’s Properties as needed; assign a button
(or scroll bar) to the ActiveX control and set its Properties;
then use Microsoft’s Script Wizard to link the button’s Events
to Via 10 ActiveX parameters or link other Events and
Actions if needed for your application.
Important note: Even though Via 10 ActiveX controls must
be inserted in each web page where Via 10 controls are
needed, the Via 10 controls that are displayed in FrontPage
2000’s Normal window are not visible when viewed in
Internet Explorer or in the Preview window in FrontPage
2000.
The James A. Michener version of these examples is
found on our web site. [This is the extra added advantage of
receiving an early Via 10 – the Manual is 99.8 percent done.
The 0.2% is on our web site.] Go to www.rane.com/via10.htm
for other future downloadable updates such as sample HTML
pages and additional ActiveX controls.
