Communication device, abnormality determination device, method, and storage medium

A method of operating an onboard communication device, the method comprising:

• performing, on received data, a communication abnormality determination based on detection rules;
• comparing a data length code (DLC) of the received data, which has been determined by the determination to represent a communication abnormality during a current trip using the performed communication abnormality determination, with a DLC of data that has been determined to represent a communication abnormality using the performed communication abnormality determination in a previous trip;
• comparing a transmission period of a frame of the received data, which the processor has determined to represent the communication abnormality during the current trip, with a transmission period of a frame of the data that the processor has determined to represent the communication abnormality using the performed communication abnormality determination during the previous trip;
• setting a mask that suppresses determination of the received data as representing a communication abnormality for each of the DLC and the transmission period of a frame, for each controller area network identifications (CAN IDs) of communication frames;
• when the mask is set for a DLC of data of a predetermined CAN ID, not performing the communication abnormality determination based on comparing respective DLCs on the data of the predetermined CAN ID:
• and when the mask is set for a transmission period of a frame of data of a predetermined CAN ID, not performing the communication abnormality determination based on comparing respective transmission periods of frames on the data of the predetermined CAN ID.

A non-transitory computer readable storage medium that stores a program executable by a computer to perform communication processing, the communication processing comprising:

• performing, on received data, a communication abnormality determination based on detection rules;
• and
• comparing a data length code (DLC) of the received data, which has been determined by the communication abnormality determination to represent a communication abnormality during a current trip using the performed communication abnormality determination, with a DLC of data that has been determined to represent a communication abnormality using the communication abnormality determination during a previous tip;
• comparing a transmission period of a frame of the received data, which the processor has determined to represent the communication abnormality during the current trip, with a transmission period of a frame of the data that the processor has determined to represent the communication abnormality using the performed communication abnormality determination during the previous trip;
• setting a mask that suppresses determination of the received data as representing a communication abnormality for each of the DLC and the transmission period of a frame, for each controller area network identifications (CAN IDs) of communication frames;
• when the mask is set for a DLC of data of a predetermined CAN ID, not performing the communication abnormality determination based on comparing respective DLCs on the data of the predetermined CAN ID;
• and
• when the mask is set for a transmission period of a frame of data of a predetermined CAN ID, not performing the communication abnormality determination based on comparing respective transmission periods of frames on the data of the predetermined CAN ID.