Abnormality detection method and system having sleep mode check function

An abnormality detection system comprising:

• a network including a plurality of electronic control units for respective controlled devices, the control units being constructed to transmit respective data frames;
• a communication line;
• and
• an abnormality detection unit connected to the network through the communication line for collecting abnormality monitor information of the controlled devices based on the transmitted data frames,
• wherein the control units are constructed to shift to a sleep mode after a predetermined wait period under a condition that no activation cause is present,
• wherein the control units are constructed to transmit, in the data frames, identification information thereof and sleep not good information indicative of sleep disablement when the activation cause is present, and
• wherein the detection unit includes transition detection means for detecting a transition of the controlled devices from an operation condition to an operation stop, and activated unit detection means for monitoring the transmitted sleep not good information after the controlled devices shifted to the operation stop condition and detecting the control unit which remains activated after the predetermined wait period.