Manual-8
Hardware 4: Versatile Output Port (VOP)
The VOP provides an impeccable place to connect
indicators (LEDs, small lamps), relays and/or other logic
inputs. Each of the eight open collector outputs are indepen-
dently programmable using the
Via10VOPX
ActiveX control.
Use each of the eight VOPs to independently drive indicators
or relays. Current on each of the eight open collector ports is
limited to 100 mA maximum when all 8 ports are driven; 200
mA maximum when 4 ports are driven. The VOP’s internal
12 VDC supply pin is limited to 100 mA maximum. Each
open collector VOP output includes a clamping diode for
switching inductive loads. Any combination of lamps, LEDs,
relays and logic input ports can be used as long as the 100
mA (8 driven) current limitation is not exceeded. So choose
your parts wisely. External power supplies may be necessary
when using larger current capacity relays that require more
than the 12 VDC/100 mA maximum allowed by the VOP. Up
to a 40 volt external power supply can be used with the VOP
as long as the external supply is ground referenced (i.e.,
connected) to the VOP GND pin. The VOP update rate is
dominated by the network transmission speed and is updated
each time the VOP data is renewed or changed using the
Via10VOPX
ActiveX control.
Software and Applications
ActiveX and Software issues
ActiveX controls (defined in the next section) are of
concern to the pro audio community. This technology allows
designers of computer-controlled sound systems to create
common front-end software control panels that operate
different manufacturers’ units, without having to know
anything about their internal code or algorithms. This is
powerful. Once more manufacturers jump on the ActiveX
bandwagon, systems designers will no longer be limited by
the products offered by a single, platform-specific (i.e., closed
architecture) manufacturer. Each ActiveX control is made up
of Properties and Events. ActiveX control Properties are
values associated with the control which might include such
things as level settings, mute condition and meter readings.
ActiveX control Events tell the computer something signifi-
cant has happened, such as a switch closure or clip detection.
ActiveX allows the manufacturer to create an object (a piece
of software code) which fully describes a device, while hiding
the implementation details such as protocol from the pro-
grammer. By hiding the communication details, there is no
longer a need for different manufacturers’ devices to agree on
protocol. This lack of a protocol standard means that coopera-
tion between manufacturers is not required. It allows each
manufacturer to choose the best protocol for their devices.
For example, no longer would you need to know that the
17
th
byte of a 32-byte status message meant that the unit’s
second output channel was muted. With an ActiveX control,
you might simply refer to the device’s output 2 mute status as
“Device1.Out2Mute”.
What is ActiveX anyway? ActiveX is a Microsoft
developed software technology released in 1996. ActiveX,
formerly called OLE (Object Linking and Embedding), is
loosely based on the Component Object Model (COM), but
provides substantially different services to developers. At this
point, you might think: WHAT!?^* But keep reading! An
ActiveX control is a unit of executable code (such as an .EXE
file) that follows the Active X specification for providing
software objects. This technology allows programmers to
assemble reusable software controls into applications and
services. However, software development using ActiveX
technology should not be confused with Object-Oriented
Programming (OOP). OOP is concerned with creating
objects, while ActiveX is concerned with making objects
work together. Simply stated, ActiveX is a technology that
lets a program (the ActiveX control) interact with other
programs over a network (e.g., the Internet or Ethernet),
regardless of the language in which they were written.
ActiveX controls can do similar things as Java, but they are
quite different. Java is a programming language, while
ActiveX controls can be written in any language (e.g., Visual
Basic, C, C++, even Java). Also, ActiveX runs in a variety of
applications, while Java and Javascript usually run only in
Web browsers.
ActiveX controls can be used in web pages and within
visual programming languages such as Delphi, Power
Builder, Visual Basic and even in tools such as Lab View.
In English, for our pro audio applications, objects are the
VOP (Versatile Output Port)
VOP
+12
12 VOLTS
OR
OR
OR
RELAY
COIL
LOGIC
INPUT
LAMP
LED
8 PORTS DRIVEN: 100 mA
4 PORTS DRIVEN: 200 mA
= | MAX
GND
GND
GND
+V (VP TO 40 VOLTS)
OR
OR
OR
PORT 1 SHOWN, 2 THROUGH 8 THE SAME
EXTERNAL
POWER
SUPPLY
1
100 mA= | MAX
