With regard to an instrument wherein a plurality of phase operations are carried out, the type of failure or the phase in which the failure has occurred is determined and, in accordance with the result of the determination, an alarm signal is generated. Provided that the failure details and the phase in which the failure has occurred can be determined from the generated alarm signal, it is possible, using a configuration wherein an alarm signal having a pulse number corresponding to the phase in which a failure has occurred is generated, or a configuration wherein an alarm signal having a pulse width corresponding to the phase in which a failure has occurred is generated, to determine the type of failure that has occurred and the phase in which the failure has occurred from the pulse number and pulse width.