A bus subscriber device (16, 18, 20; 40) for connection to a line-redundant serial data bus, over which data is exchanged according to a predefined protocol, comprising the following features: a data transmission unit, at least two data receiving units (50, 52) that are connected in parallel, a line selection logic, and at least two bus communication interfaces (42, 44) for connecting to a corresponding number of lines of the data bus, wherein each of the data receiving units (50, 52) is connectable via an associated bus communication interface (42, 44) to an assigned line of the data bus and comprises means for receiving a data block from the associated line of the data bus and means for forwarding the received data block to the line selection logic, and wherein the line selection logic comprises means for selecting a line of the data bus as a receiving line and forwarding the received data block over the selected receiving line, characterized by: at least two timer devices (56, 58) that are associated with the at least two data receiving units (50, 52), wherein the data transmission unit is connectable via the bus communication interfaces (42, 44) to the lines of the data bus and the line selection logic is configured to assign, dependent on the result of the selection of one of the lines as receiving line of the data transmission unit, the timer device (56, 58), which is assigned to the data receiving unit (50, 52) for the selected receiving line. a data transmission unit, at least two data receiving units (50, 52) that are connected in parallel, a line selection logic, and at least two bus communication interfaces (42, 44) for connecting to a corresponding number of lines of the data bus, wherein each of the data receiving units (50, 52) is connectable via an associated bus communication interface (42, 44) to an assigned line of the data bus and comprises means for receiving a data block from the associated line of the data bus and means for forwarding the received data block to the line selection logic, and wherein the line selection logic comprises means for selecting a line of the data bus as a receiving line and forwarding the received data block over the selected receiving line, characterized by: at least two timer devices (56, 58) that are associated with the at least two data receiving units (50, 52), wherein the data transmission unit is connectable via the bus communication interfaces (42, 44) to the lines of the data bus and the line selection logic is configured to assign, dependent on the result of the selection of one of the lines as receiving line of the data transmission unit, the timer device (56, 58), which is assigned to the data receiving unit (50, 52) for the selected receiving line. at least two timer devices (56, 58) that are associated with the at least two data receiving units (50, 52), wherein the data transmission unit is connectable via the bus communication interfaces (42, 44) to the lines of the data bus and the line selection logic is configured to assign, dependent on the result of the selection of one of the lines as receiving line of the data transmission unit, the timer device (56, 58), which is assigned to the data receiving unit (50, 52) for the selected receiving line.