The present disclosure comprises a method, a communication module, and a system for transmitting diagnosis data of a field device that is connected to a superordinate unit via a communication loop. The communication module is connected to the communication loop in parallel with the field device. The method includes the continual storage of electrical energy in the communication module by a transducer unit within the communication module that captures an electrical and/or physical variable and converts it into electrical energy. The method includes polling the diagnosis data of the field device by the communication module and wireless transmission of the polled diagnosis data to a reception unit by the communication module.