Photovoltaic systems which are environment friendly, clean, and modular are highly in demand. These systems can be planned and constructed from several watts to MWs. They are applied as rooftop systems or ground mounted power plants. For whole photovoltaic power plant applications, electrical data and fault events on photovoltaic power plants should be collected and analyzed to monitor and fix whole system. In this study, a rooftop photovoltaic power plant which was planned with a new generation data logger module, was analyzed. With this module, electrical data as string voltage, string current, power, current, and voltage of inverter outage etc., can be collected and transferred to a web based server station. Finally, whole electrical data from a photovoltaic power plant can be monitored and analyzed by an operator thanks to this data logger module.