| 摘要 |
PROBLEM TO BE SOLVED: To provide a system, a device and a method which conveniently provide user with electric vehicle charging related information.SOLUTION: An add-on communication device is attached to a cable installation type charging control device integrally attached to a cable assembly for charging an electric vehicle. The add-on communication device comprises a control unit and a plurality of communication modules for communicating with a terminal device. The control unit determines a first communication module for transmitting a message among the plurality of communication modules. When there is no normal reception of an acknowledgement message indicating that the terminal device has normally received the message, the control unit determines a second communication module for retransmitting the message among the plurality of communication modules except the first communication module. |
