A communication apparatus for message exchange with charging equipment, comprising: a communication unit provided to be coupled to the charging equipment through a first communication channel; and a control unit coupled to the communication unit through a second communication channel, characterised in that the control unit is configured to: identify a value set to a time-out flag associated with a request message, when transmitting the request message to the communication unit through the second communication channel at a first time point, determine a target polling time based on the identified value, and periodically check whether a response message from the charging equipment is received by the communication unit at each target polling time for a waiting period from the first time point to a second time point at which a time-out time associated with the request message has passed from the first time point, wherein when the identified value is equal to a first value indicating that time-out of the corresponding message did not occur at a charging procedure of a previous cycle, the control unit is configured to determine the target polling time to be equal to a sum of a default time and a previous polling time, each associated with the request message, and wherein when the identified value is equal to a second value indicating that time-out of the corresponding message occurred at a charging procedure of a previous cycle, the control unit is configured to determine the target polling time to be equal to a reference polling time associated with the request message, the reference polling time being equal to or less than the previous polling time. a communication unit provided to be coupled to the charging equipment through a first communication channel; and a control unit coupled to the communication unit through a second communication channel, characterised in that the control unit is configured to: identify a value set to a time-out flag associated with a request message, when transmitting the request message to the communication unit through the second communication channel at a first time point, determine a target polling time based on the identified value, and periodically check whether a response message from the charging equipment is received by the communication unit at each target polling time for a waiting period from the first time point to a second time point at which a time-out time associated with the request message has passed from the first time point, wherein when the identified value is equal to a first value indicating that time-out of the corresponding message did not occur at a charging procedure of a previous cycle, the control unit is configured to determine the target polling time to be equal to a sum of a default time and a previous polling time, each associated with the request message, and wherein when the identified value is equal to a second value indicating that time-out of the corresponding message occurred at a charging procedure of a previous cycle, the control unit is configured to determine the target polling time to be equal to a reference polling time associated with the request message, the reference polling time being equal to or less than the previous polling time. identify a value set to a time-out flag associated with a request message, when transmitting the request message to the communication unit through the second communication channel at a first time point, determine a target polling time based on the identified value, and periodically check whether a response message from the charging equipment is received by the communication unit at each target polling time for a waiting period from the first time point to a second time point at which a time-out time associated with the request message has passed from the first time point, wherein when the identified value is equal to a first value indicating that time-out of the corresponding message did not occur at a charging procedure of a previous cycle, the control unit is configured to determine the target polling time to be equal to a sum of a default time and a previous polling time, each associated with the request message, and wherein when the identified value is equal to a second value indicating that time-out of the corresponding message occurred at a charging procedure of a previous cycle, the control unit is configured to determine the target polling time to be equal to a reference polling time associated with the request message, the reference polling time being equal to or less than the previous polling time.