Yet, all thermostats receive their set points in the form of a PLC message, unless a given unit is returned to a different set point by a local command. In this case, look at the system as composed of one simple programmable-thermostat driving the other thermostats in the house. It is the remote collection of consumption data from your utility meters and it makes use of telephony, radio frequencies, power lines, and satellite communication technologies to move around its information. Variable rate information may be downloaded in the opposite direction, enabling Demand Side Management and resulting in savings to customers. AMR systems that use other communication links can use the PLC-1 to transfer messages into customer's homes, either from a concentrator or directly from the utility's meter.
Utilities can monitor and control Internet-enabled systems over the Internet.
Home automation can link lighting, entertainment, security, telecommunications, heating, and air conditioning into one centrally controlled system. HA is different from Home Networking, the latter being dedicated to data communication. It is true that HA may use one or more networks to link devices and sub-systems, but this control network is still physically different from data networks. HA networks are designed to carry very small amounts of control information, while data networks are designed to carry large amounts of data, generally at the highest possible speed. PLC is an essential technology for HA, because it enables the installation of a control-oriented communication network without the need to tear down walls in order to install dedicated wiring.