A subscriber station for a serial bus system including a communication control device for controlling a communication with another subscriber station and a transceiver device for sending a transmit signal produced by the communication control device as a frame to a bus of the bus system. The bit time of a signal sent to the bus in the first communication phase differs from a bit time of a signal sent in the second communication phase. The communication control device produces the transmit signal, in a first operating mode, for a first frame that is designed according to a specified communication protocol with which other subscriber stations in the bus system communicate, and is designed to produce the transmit signal, in a second operating mode, for a second frame that assigns to at least one bit a different function than is assigned to the bit in the specified communication protocol.