A power system comprising: a power device group comprising a power device; communication devices connected through a short range communication network with each other and connected to the power device; and a monitoring/controlling device connected to the communication devices in a wired manner, and transmitting and receiving state information data and control data of the power device through the communication devices, wherein the communication devices each comprise: a first communication unit connecting the communication devices through the short range communication network with each other and connected to the power device, and a second communication unit connected to the monitoring/controlling device in a wired manner, wherein the monitoring/controlling device comprises: a communication unit connected to each of the communication devices in a wired manner; a storage unit storing information on each of the communication devices and a recovery command message according to a state of each of the communication devices; and a controller checking the state of each of the communication devices and the communication state of a wired communication line of each of the communication devices, and when one of the communication devices is in an abnormal state, outputting the recovery command message to the one of the communication devices; wherein the communication devices comprise a first communication device and a second communication device, and when the state of the first communication device and the communication state of the wired communication line of the first communication device are in the abnormal state, the controller outputs information related to the first communication device in the abnormal state and the recovery command message to the second communication device in the normal state and connected to the first communication device in the abnormal state; and wherein the second communication device transmits the recovery command message to the first communication device in the abnormal state. a power device group comprising a power device; communication devices connected through a short range communication network with each other and connected to the power device; and a monitoring/controlling device connected to the communication devices in a wired manner, and transmitting and receiving state information data and control data of the power device through the communication devices, wherein the communication devices each comprise: a first communication unit connecting the communication devices through the short range communication network with each other and connected to the power device, and a second communication unit connected to the monitoring/controlling device in a wired manner, a first communication unit connecting the communication devices through the short range communication network with each other and connected to the power device, and a second communication unit connected to the monitoring/controlling device in a wired manner, wherein the monitoring/controlling device comprises: a communication unit connected to each of the communication devices in a wired manner; a storage unit storing information on each of the communication devices and a recovery command message according to a state of each of the communication devices; and a controller checking the state of each of the communication devices and the communication state of a wired communication line of each of the communication devices, and a communication unit connected to each of the communication devices in a wired manner; a storage unit storing information on each of the communication devices and a recovery command message according to a state of each of the communication devices; and a controller checking the state of each of the communication devices and the communication state of a wired communication line of each of the communication devices, and when one of the communication devices is in an abnormal state, outputting the recovery command message to the one of the communication devices; wherein the communication devices comprise a first communication device and a second communication device, and when the state of the first communication device and the communication state of the wired communication line of the first communication device are in the abnormal state, the controller outputs information related to the first communication device in the abnormal state and the recovery command message to the second communication device in the normal state and connected to the first communication device in the abnormal state; and wherein the second communication device transmits the recovery command message to the first communication device in the abnormal state.