An angiographic injector system and a method of controllably delivering medical fluid to a patient from an angiographic injector system are disclosed. A multiple processor control system is used to actively control the injection process and to monitor sensed functions of the system. The multiple processors provide dual redundancy safety circuits for critical control functions such as syringe motor drive speed and current. A motor/servo-amplifier nested control function is also disclosed. A unique method and apparatus are disclosed for establishing injection parameter default values just prior to an injection procedure that are based on physiological values of the patient to be treated. The injector system uses an interactive display panel that presents sequenced set-up screens to the user and which enables the user to select injection procedures, parameters and other modes of operation directly through the interactive panel.