Here's a simple VB2008 express X10 project you can download to test.
You can look at the code to see how it all works.
This program monitors X10 traffic and the traffic appears in the window.
I use this same traffic monitor in my X10 projects.
There's a few buttons that turn on and off X10 devices to demo how that is done.
There is a query button that will give the satus of G16
0= Off and 1= On
Change the devices to suit your needs
I just picked G16 because I use it and could test the device and software
Here is the link to a zip file that contains the VB2008 express project shown above.
Unzip the project and open the .sln file in VB2008 express
http://www.el34world.com/Misc/home/Files/X10Monitor.zip
Fixing my X10 signal problems
Strange X10 device problems and how I fixed them
My favorite X10 merchant
Fast shipping, only charges what the shipping cost him and great service
Project #1
Convert a wireless motion sensor and wireless base unit receiver to trigger a X10 Powerflash unit.
Project #1 is used to trigger this macro
Project #2
Convert a motion sensor that runs on 120vac to trigger a X10 Powerflash unit.
This motion sensor was removed from a set of motion spot lights.
Project #3
Install a current sensor circuit in a powerstrip.
Anything that is plugged into the powerstrip and then is turned on will trigger a X10 Powerflash unit.
The Powerflash unit can then turn on other X10 modules which lets you control other devices remotely.
In my case, I turn on 3 machines
in my shop.
These machines makes lots of nasty dust.
Turning on any of these 3 machines will automatically turn on my dust collection shop
vacuum.
Project #4
Combine a video surveillance system with AHP's Iwatch camera software.