Add intelligent control to your home's environmental systems and save money on energy costs with the most reliable and powerful climate control system available! This high performance thermostat receives signals using the RS-485 protocol -- the ultimate in signal strength and reliability. RS-485 signals are not only stronger than RS-232 signals, but they also travel further along common Cat. 5 cable (up to 4,000 ft.), resulting in an easier installation without the additional expense of amplifiers, couplers and repeaters. And unlike X10, RS-485 signals are sent along a dedicated connection, so you won't have to worry about lost X10 signals or the remote possibility of a stray X10 signal from one of your neighbors affecting your home's temperature. The thermostat consists of two components: the controller that mounts near the air handling equipment and the wall-mounted display unit, allowing you to control temperature via several easy-to-use methods. To make changes locally, simply push the buttons on the wall-mounted unit's thermostat-like user interface. For remote or automated control via RS-232/485 remote interfaces, simply make the adjustments from your RS-232/485 home control system, like the Stargate or TimeCommander Plus. The unit even accepts ASCII-based freeform character strings, making it easy for programmers to develop their own custom programs! A six-page programmer's reference guide explains all the remote command protocols. The thermostat controls all standard functions of gas/electric or heatpump HVAC systems, including heating (two-stage heating on heatpump systems), cooling and fan control. It connects to HVAC systems via standard thermostat connections, and connects to the wall-display unit via a 4-wire connection (2 power, 2 data). The controller also offers fuse-protected relay outputs to the mechanical system, responds to polling requests by sending current temperature, setpoint, mode and fan status.