Abstract: A transmitter and a receiver are paired that use the same power line and power module. The transmitter associates an identification number with a command message so that a receiver can ascertain that a command message is intended for the receiver. The transmitter uses the time from the power up to the first zero crossing of the AC signal to generate a matching seed for both transmitter and receiver. The transmitter generates an identification number by incrementing a counter each incremental time interval between power up and the occurrence of the first zero crossing of the AC signal and sends the generated identification number to the paired receiver after power up but before a predetermined time interval. The receiver stores the generated identification number and compares the stored identification number with a received identification number that is received in a subsequent command message.

Abstract: The present invention provides methods and apparatuses that support the transfer of data from a thermostat unit to a controller unit to control a variable speed heating, ventilation, and air conditioning (HVAC) system. The duty cycle of a signal (that is sent from a thermostat unit to a controller unit) is adjusted in accordance with a temperature difference between the ambient temperature of an environmentally controlled space and a set temperature. The controller unit measures the duty cycle to determine the temperature difference and adjusts the speed of a blower motor or compressor in accordance with the temperature difference. The signal is switched on and off, in which the AC waveform is conducted and blocked by the thermostat unit and received by the controller unit. The controller unit measures the duty cycle of the received signal, determines the temperature from the duty cycle, and adjusts the speed from a predetermined relationship.

Abstract: The present invention supports pairing a transmitter and a receiver that use the same power line and power module. The transmitter associates an identification number with a command message so that a receiver can ascertain that a command message is intended for the receiver. The transmitter uses the time from the power up to the first zero crossing of the AC signal to generate a matching seed for both transmitter and receiver. The transmitter generates an identification number by incrementing a counter each incremental time interval between power up and the occurrence of the first zero crossing of the AC signal and sends the generated identification number to the paired receiver after power up but before a predetermined time interval. The receiver stores the generated identification number and compares the stored identification number with a received identification number that is received in a subsequent command message.