A method for fault reaction, fault isolation, and graceful degradation in a robotic system including a user console in communication with a robotic arms cart having a supervisor processor, a plurality of arm processors (210,220,230,240) in communication with the supervisor processor, and a plurality of robotic arms (111,113,115,117) in communication with the supervisor processor and the plurality of arm processors (210,220,230,240), wherein each robotic arm of the plurality of robotic arms (111,113,115,117) includes one or more nodes (211, 212, 213, 214) for controlling one or more motors (21,23,25,27) and one or more brakes (22,24,26,28), and a fault reaction logic, FRL, line (215,225,235,245) coupled to each of the one or more nodes (211,212,213,214), the respective arm processor (210,220,230,240), and the supervisor processor so that fault notifications and recovery notifications may be quickly propagated through the robotic arm (111,113,115,117), the method comprising: by each of the one or more nodes (211,212,213,214) in each of the plurality of robotic arms (111,113,115,117), continuously monitoring signals in the respective node to detect a fault in the node and monitoring the FRL line (215,225,235,245) for notifications issued by the respective arm processor or another node in the respective node's robotic arm; issuing a fault notification on the FRL line (215,225,235,245) at a failed node in a failed arm of the plurality of robotic arms (111,113,115,117), wherein a failed node comprises a node in which a fault has been detected and a failed arm comprises an arm containing the node in which the fault has been detected; detecting the fault notification on the FRL line (215,225,235,245) from the failed node in the failed arm of the plurality of robotic arms (111,113,115,117); placing the failed node in the failed arm into a safe state, wherein the safe state isolates the failed node by disabling one or more motors (21,23,25,27) and engaging one or more brakes (22,24,26,28) in the failed arm to prevent further movement of the failed arm; determining whether a fault associated with the fault notification should be treated as a system fault or a local fault, wherein the system fault affects a performance of at least one other robotic arm of the plurality of robotic arms (111,113,115,117), and wherein the local fault affects performance of only the failed arm; and placing all non-failed arms of the plurality of robotic arms (111,113,115,117) in the safe state only if the fault is to be treated as a system fault. by each of the one or more nodes (211,212,213,214) in each of the plurality of robotic arms (111,113,115,117), continuously monitoring signals in the respective node to detect a fault in the node and monitoring the FRL line (215,225,235,245) for notifications issued by the respective arm processor or another node in the respective node's robotic arm; issuing a fault notification on the FRL line (215,225,235,245) at a failed node in a failed arm of the plurality of robotic arms (111,113,115,117), wherein a failed node comprises a node in which a fault has been detected and a failed arm comprises an arm containing the node in which the fault has been detected; detecting the fault notification on the FRL line (215,225,235,245) from the failed node in the failed arm of the plurality of robotic arms (111,113,115,117); placing the failed node in the failed arm into a safe state, wherein the safe state isolates the failed node by disabling one or more motors (21,23,25,27) and engaging one or more brakes (22,24,26,28) in the failed arm to prevent further movement of the failed arm; determining whether a fault associated with the fault notification should be treated as a system fault or a local fault, wherein the system fault affects a performance of at least one other robotic arm of the plurality of robotic arms (111,113,115,117), and wherein the local fault affects performance of only the failed arm; and placing all non-failed arms of the plurality of robotic arms (111,113,115,117) in the safe state only if the fault is to be treated as a system fault.