| 摘要 |
PROBLEM TO BE SOLVED: To enhance reliability on radio communication.SOLUTION: A load control device twice transmits a transmission frame (radio signal) at different timings to an operation terminal unit, whereby the probability that the operation terminal unit receives the radio signal is increased and thus reliability on the radio communication can be enhanced. A communication controller of the operation terminal unit re-transmits a transmission frame (radio signal) containing a control command from a communication unit when being incapable of receiving any ACK message, whereby the reliability on radio communication can be greatly enhanced as compared with a case where re-transmission is not performed. Furthermore, a load control system increases the probability that a reply frame (radio signal) returned from the load control device is received at a communication device (the operation terminal unit and a radio adaptor device), so that the reliability on radio communication can be enhanced.SELECTED DRAWING: Figure 8 |
