A data bus node, being a control node or a sensor node and being arranged to communicate over a TDMA data bus. The node includes a time signal processing device being configured to define a TDMA time slot transmission schedule for at least the node. A switch is configured to either connect or isolate a transmission path of the node to the bus and is configured to be controlled by the TDMA time slot transmission schedule for the node via a bus transmission access control device. The bus transmission access control device is configured to be further controlled by at least one external control signal via at least one external data transmission link being physically separated from the bus. A fault tolerant data bus system includes such a bus node and an aircraft exploiting the node/system. The babbling idiot problem is solved and at the same time the node/s/system fail silent behavior is enhanced.