This a hardware problem, but i'll explain the process so it makes
sense. I need to query an SQL database so that under certain
conditions a light will go on, and off in others. Specifically, if a
call is in queue in our Avaya IP Office phone system then a light will
go on, and if the queue goes away then the light will go off. (big red
light in the middle of the room, alternative would be electric chair
shockers so people know there's a call in queue, ok just joking about
the chair shockers, we'll stay with the light). What we want someone
to do is spec (or set up if in San Francisco) a pc and whatever card
is needed so when the software says so, it switches power on to
another device, and then off when the software signals. If you can
write the software bit great, if not just the hardware bit. If you
have experience with Avaya IP phone system even better. I've priced
this to value this link to the site that will do it for us, but if
there's no links out there and you can design it i'll take that at a
higher price to allow for time if this questions isn't answered in a
few days.

headsetsdotcom,

When I saw your question, the first thing that came to mind is that it
presents a situation similar to home automation.

X10 is a protocol intended for home automation. It is a mechanism for
sending signals to and from X10 devices through an existing AC power
system, as would already exist in a home or business. SmartHome (tm)
was listed in a Google Search as one of the top results when searching
for X10 technology venders. They have a good page that explains X10
technology here:

http://www.smarthome.com/about_x10.html

The solution using X10 technology would be to get a computer
interface, and a light controller. The computer interface would be
used to send signals to the light controller by a Visual Basic (or
other) application that would poll the SQL database.

Here is a computer interface that includes a software development kit,
with Visual Basic source code: http://www.smarthome.com/1132.html

Here is an in-socket light controller:
http://www.smarthome.com/2005.html

The advantage of using X10 technology is that in the future, this sort
of system could easily be expanded. Multiple lights for multiple
conditions could easily be added, and things other than lights can be
controlled. With X10, anything that plugs into AC power can be
controlled. Also, X10 technology is quite inexpensive.

I hope this is an optimal solution for your situation. As a technology
enthusiast, I am interested in hearing back as to the implementation
of this.

--
samrolken-ga

I do understand and appreciate the use of X-10 pc interface to do the same.
But I do need to warn you that X-10 is susceptible to spurious triggers
(might  originate out of a X-10 circuit connected somewhere on the same
transformer that your facility is powered). Also X-10 sockets could go
bad sometimes very easily(esp. the screw on types). If you want a reliable
solution(and are not in need of the remote control provided by X-10), you
could just buy any pc-serial/pc-parallel interface kits along with a relay.
most of these interfaces should come with simple programs to control the
port. The advantage is the reliability, simplicity(you could just dump
some raw data to the port from any application) and security(no false triggers
unless a virus gets hold of the port, and knows how to control the device).

Regards
ldavinci-ga

I agree with Idavinci.  There are any number of these devices on the
market.  If you are interested in kits, the Velleman has a set of
computer interface boards and light controls.  The cost of them is in
the $100 range.  You can find their Belgian web site as
http://www.velleman-kit.com.  I have put a few together, and they are
not bad;  they are available in the US and Canada without problems. 
Just put the kit number into Froogle and you can find them.