Owner's Manual (Complete)

The Home Control Assistant
1
Chapter 24
HCA Client-Server
Everything described in the User Guide up to this point describes what is called stand-alone HCA.
It works just like most other Windows applications – you install it on your Windows computer,
start it, work with it, and leave it running so it can control your home.
But HCA can also operate in client-server mode. This is what is called
Client-Server HCA. If you
are unfamiliar with the term “client-server” here is a definition:
Client/server describes the relationship between two computer programs in which one program,
the client, makes a service request from another program, the server, which fulfills the request.
Although the client/server idea can be used by programs within a single computer, it is a more
important idea in a network. In a network, the client/server model provides a convenient way to
interconnect programs that are distributed efficiently across different locations
Client-Server HCA consists of these components:
 The HCA Server loads and “executes” your automation design. His application has a very
minimal user interface. It communicates with all your attached interfaces, runs schedules and
programs contained in your design, and handles triggers for programs and devices. You can
think of the server as giving the same function as stand-alone HCA after you loaded your
design and then you didn’t touch the UI. Your design just runs in the background.
 There is no separate Windows based HCA Client application to pair with the server. The
client is just HCA running in client-mode. The same HCA executable works in both stand-
alone mode and as a client to the HCA Server.
What can HCA do when operating as a client? It can do anything that you can do with stand-alone
HCA except for creation of a whole new design. From a client you can modify programs, add new
devices, scan an Insteon network, control devices, etc. The experience working with the client
should be the same as when working with stand-alone HCA.
A very important point is that multiple clients can be connected to the HCA server at one time.
When you do this, any change made on one client to the state of an object – on, off, or dim – or a
change to the design – adding a new device, changing a program etc - automatically updates the
other clients with those same changes.
Why would you want to use HCA Client-Server? The major advantage of HCA is that it can
integrate all your different powerline technologies, weather, IR, wireless, and the internet with your
programming and schedules. As such it has to run 24/7 on some computer in your home. While it
is possible to run HCA on your family computer many users want to run HCA on their home server
– along with web server software, backup programs, and printers. These sorts of computers often
don’t have connected keyboards, mice, and displays. HCA Client-Server makes this possible very
simply.
You also may want to run a client on a shared computer in your home. If you configure that client
to use the Touch-Screen User Interface – described in its own chapter – then everyone can control
just those devices you want to expose. And they are prevented from making any design changes.
Note: Don’t be confused with the term “HCA Server”. HCA continues to have the web based
client – what is called the “Web Component”. Nor is the HCA Server a “Windows
Service”. The HCA Server is just another Windows application. And, unlike the Web
Component which can be accessed from any computer that has a compatible browser, the
HCA client – being just HCA – requires Windows XP, Vista or Win 7.