Owner's Manual (Complete)

The Home Control Assistant 1
Chapter 17
Restart
HCA is a program different than others that you may run on your computer. Unlike an email
program or a word processor which you may start and edit many times a day, HCA is designed to
be running almost all the time. Because of this when HCA is started and stopped special things
happen.
Whenever HCA is started it attempts to pick up where it left off when it was shutdown. Of course,
if it is starting for the very first time HCA has no prior state so it just begins. But from that point
on when HCA is started, it is restarting from some prior shutdown.
This restart could happen after a power failure or after you selected Shutdown from the File menu
While restart after a normal shutdown will be explained, the most important use of this feature is to
recover after a power failure.
Power failure detection and recovery is a very complex area. In general terms, the goal of power
failure recovery is to restore the state of HCA and your home to what it would have been if the
power had not failed.
Example: Suppose that HCA is active and the power fails at 7 p.m. When the power is restored at
8 p.m., HCA attempts to:
1. Make sure that lights that were on at 7 p.m. are turned on.
2. Make sure that any lights that should have come on between 7 p.m. and 8 p.m. also come on.
3. Make sure lights that were on at 7 p.m., and were scheduled to be off by 8 p.m. are not on.
Of course, more than just lights may be involved, and HCA checks and corrects status for
all
participating devices, programs, and groups. In fact, HCA will restart programs that were running
when the power failed at the point they were interrupted. If the programs were executing delay or
wait elements at that time, they are restarted and take into account the lost time due to the power
failure.
This chapter discusses power failure and recovery, and includes:
 Types of power supply
- No uninterruptible power supply
- Using uninterruptible power supply
 Controlling restart
 Restart from a normal shutdown
 Some hints about power failure and recovery
Types of power supply
HCA handles power failure recovery differently, depending on whether the computer is or is not
connected to an Uninterruptible power supply (UPS). HCA has been designed to work with any
UPS.