Hello,
I can't find a list of items I have to buy, to make the HVAC controllable with the TSU9600. If anyone know's where to look, please let me know. Thanks.

I can tell you how my home works.

My Thermostats are RCS units which communicate via RS485. I chose them because they are attractive and directly replace the existing wall thermostats using the existing wires.

At the system (AC/Heat) end, the old thermostat wires connect to a control unit that then talks to the new thermostats and to the HVAC system. Easy to wire in.

You then wire the control units (one per zone/thermostat) to a central location using their (RCS) hub and doing it in star toplogy. The hub supplies power, so in my house it is on the same UPS as the house automation server. The hub communicates to the outside world with RS232. You now connect the TSU9600 through an extender which is connected to the RCS Hub via RS232 and prepare to do some programming. The sequences are all Ascii based, and it is a master slave system so the TSU9600 would query/command the system. Fairly easy I imagine. You can control Set point(Hi and Lo), Fan mode (Auto, Continuous), System mode (On Cooling, Heating, Auto). You can query modes, set points and current temperature.

I chose this route because:

1) Easy retrofit

2) Stands alone, the thermostats just work although they do not do auto setback. If my world crashes (which it never does (:-); the system still operates. Setback and temperature/mode adjustements are all commanded by the controller or manually at the thermostat

3) Does not confuse repairmen who service the system, they just see a thermostat.

In my case the controller is a HomeSeer Home Automation system which is soon to be controlled by a TSU9600.

If it was just a 9600, I would have the 9600 run a "I am docked program" to do such things as setback and all else since when docked, the 9600 stay awake. Unfortunately there is no way I know of to tell if the 9600 is docked (would be a nice feature) or have it automatically run an activity when it is docked or undocked.

I did the above about 8 years ago. If I were doing it today I would use TCPIP based units such as the ones from Proliphix which have an internal web server and can be dealt with by a browser or TCPIP. They have complete self contained functionality and run about $300 per thermostat. I am slowly converting all control in my home to be TCPIP based.

The script is written for an Aprilaire 8870 thermostat. You will need it, an 8811 protocol adaptor (RS485 to RS232), and depending on the number of thermostats, a distribution panel and power transformer which supports up to 8 thermostats.

Thanks for the replies, I think I will go witht he Aprilaire 8870 since it already has a prontoscript available for it. Would I need a system controller? ( it's the most expensve piece about $800.00)