Owner's Manual (Complete)

Chapter 25—HCA for Android
4 The Home Control Assistant
The connection to the server lasts until you shutdown the phone, the connection is lost for some
reason, or disconnect by using the
Disconnect option from the menu, or you Back out of the
application to the Android main home page. If you leave
HCA for Android by pressing and
holding the Home button until the running applications popup appears and you select another
application,
HCA for Android does not close the connection to the server.
As long as the connection to the server is open, the phone receives status updates from the HCA
server and your devices change to show appropriate state.
And that’s really all there is. The various displayed pages follow the stock Android methods so if
you rotate the phone to landscape mode the displays change to use the space differently.
In addition to this description, there is also a brief Help file. Select the Help option from the menu
popup.
Primary and Secondary IP Addresses
As described above, as part of the settings the IP address of the server is specified. The
application settings have a place for a primary and a secondary IP address.
When you select the
HCA for Android Connection menu option, a connection attempt is made
using the Primary IP address. If that fails, the secondary IP address is tried.
The reason for having two IP addresses is best explained by an example. Let’s see how a user
called Bob uses the primary and secondary IP addresses.
When Bob is at home he accesses his home server using wireless. The IP address of that machine
is always 192.168.2.100. It never changes. So he makes that his primary IP address. At home
with wireless on, the connection is made using this IP address.
But when Bob is not at home he wants to access his server using BobsHome.homeDNS.org. So he
makes this his secondary IP address. Now when he is out of wireless range, the connection is
made using the phone 3G connection.
HCA for Android converts BobsHome.homeDNS.org to an
IP address and then connects to the server.
Why couldn’t Bob just use “myhome.homeDNS.org” as the one any only IP address? Well,
because of the way his internet access works that just doesn’t work. The
“BobsHome.homeDNS.org” resolves to the address of his DSL modem – as it should – and then
the modem gets confused by a home-side reference to its own address. This may or may not be
similar to your situation and we offer it only as an example.
Note: HCA for Android is smart enough in handling transitions between connections. If you
connect when using wireless, if you leave wireless range it will automatically shift to the 3G
connection with no apparent reconnection. The same thing happens if wireless becomes
available again.