There are provided methods and arrangements for communication in which, even in a case where an antenna that is not correctly connected is present in a wireless module provided with a plurality of antennas, high-performance data communication can be performed without using such antennas. RSSI values are detected from a plurality of receiving circuits of a wireless module, respectively, and a computer judges whether or not there is a significant difference between a first RSSI value detected from one receiving circuit and a second RSSI value detected from another receiving circuit. In a case where it is judged that there is the significant difference, the computer recognizes that the receiving circuit from which a larger RSSI value has been detected is connected to an antenna and the receiving circuit from which a smaller RSSI value has been detected is not connected to the antenna, and the receiving circuit recognized to be unconnected to the antenna is set to operation stop.