A communication device configured to perform non-contact communication with an IC tag , the communication device comprising: a command receiver configured to receive a command from a control device configured to control reading/writing of information from/to the IC tag ; a first communication processing unit configured to execute detection processing for detecting presence of the IC tag and, in a case where the presence of the IC tag is detected, to perform communication with the IC tag in order to read/write tag information in a first segment of the IC tag based on the command received by the command receiver ; an instruction output unit configured to output a communication instruction to another communication device so as to read/write information in a second segment of the tag information in response to a first communication result obtained by the first communication processing unit or a non-detection of the IC tag by the first communication unit ; a result receiver configured to receive a second communication result or a non-detection of the IC tag from the other communication device ; and a response processing unit configured to generate response information to the control device based on the first communication result and the second communication result in the other communication device responsive to the communication instruction, wherein the response processing unit is configured to, if the tag information in all of the segments is read successfully, merge the information in all of the segments to generate the response information, and wherein the response processing unit is configured to, if the tag information in all of the segments is not read successfully, cause repetition of, for a predetermined number of times, the non-contact communication with the IC tag , and wherein the response processing unit is configured to, if the tag information in all of the segments is not read successfully after the predetermined number of repetitions, return a response of abnormal end to the control device . a command receiver configured to receive a command from a control device configured to control reading/writing of information from/to the IC tag ; a first communication processing unit configured to execute detection processing for detecting presence of the IC tag and, in a case where the presence of the IC tag is detected, to perform communication with the IC tag in order to read/write tag information in a first segment of the IC tag based on the command received by the command receiver ; an instruction output unit configured to output a communication instruction to another communication device so as to read/write information in a second segment of the tag information in response to a first communication result obtained by the first communication processing unit or a non-detection of the IC tag by the first communication unit ; a result receiver configured to receive a second communication result or a non-detection of the IC tag from the other communication device ; and a response processing unit configured to generate response information to the control device based on the first communication result and the second communication result in the other communication device responsive to the communication instruction, wherein the response processing unit is configured to, if the tag information in all of the segments is read successfully, merge the information in all of the segments to generate the response information, and wherein the response processing unit is configured to, if the tag information in all of the segments is not read successfully, cause repetition of, for a predetermined number of times, the non-contact communication with the IC tag , and wherein the response processing unit is configured to, if the tag information in all of the segments is not read successfully after the predetermined number of repetitions, return a response of abnormal end to the control device . <EOS>