| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication terminal device that is capable of, in a network of an air conditioning system using a long transmission path utilizing frequency modulation, detecting a collision of communication data transmitted from the terminal device and improving communication reliability without increasing communication traffic.SOLUTION: A transmission signal is temporarily turned off at a timing around zero cross of a waveform of the transmission signal, during which a voltage level of a reception signal is detected to detect a signal collision. With this construction, the signal collision detection is performed with precision without being influenced by a voltage level of the transmission signal and a capture effect occurring at the time of a transmission/reception signal collision. |
