A data collecting device collecting state information of a photovoltaic device, the data collecting device comprising: a storage unit configured to store a state information group criterion; a controller configured to classify state information into a plurality of state information groups, having different state information transmission time, according to the state information group criterion for classifying the state information groups; a communication unit comprising: a reception unit configured to receive the state information including at least one of a state or a surrounding environment state of the photovoltaic device, and a transmission unit configured to transmit each of the plurality of state information groups of the photovoltaic device to a management server according to the state information transmission time of each of the plurality of state information groups; wherein the at least one of a state or a surrounding environment state of the photovoltaic device comprises a failure information, an instantaneous power generation information and an accumulated power generation information of the photovoltaic device, wherein a state information transmission time is based on a transmission period, characterised in that the transmission period of the failure information is shorter than the transmission period of the instantaneous power generation information, and the transmission period of the instantaneous power generation information is shorter than the transmission period of the accumulated power generation information. a storage unit configured to store a state information group criterion; a controller configured to classify state information into a plurality of state information groups, having different state information transmission time, according to the state information group criterion for classifying the state information groups; a communication unit comprising: a reception unit configured to receive the state information including at least one of a state or a surrounding environment state of the photovoltaic device, and a transmission unit configured to transmit each of the plurality of state information groups of the photovoltaic device to a management server according to the state information transmission time of each of the plurality of state information groups; a reception unit configured to receive the state information including at least one of a state or a surrounding environment state of the photovoltaic device, and a transmission unit configured to transmit each of the plurality of state information groups of the photovoltaic device to a management server according to the state information transmission time of each of the plurality of state information groups; wherein the at least one of a state or a surrounding environment state of the photovoltaic device comprises a failure information, an instantaneous power generation information and an accumulated power generation information of the photovoltaic device, wherein a state information transmission time is based on a transmission period, characterised in that the transmission period of the failure information is shorter than the transmission period of the instantaneous power generation information, and the transmission period of the instantaneous power generation information is shorter than the transmission period of the accumulated power generation information.