DoCAN

ISO15765-2 (UDS) and ISO15765-4 (OBD) have different values for the timeout parameter.The UDS side is looser and the OBD side is stricter.Some timeout parameters are set as performance requirements.N_Br and N_Cs.

ISO-TP has six timeout parameters.N_As, N_Bs, N_Cs, N_Ar, N_Br, and N_Cr.Single frame transmission is complete in one frame, so only N_As.Multi-frame transmission uses all parameters.ISO-TP only determines the timeout at the frame level, and the timeout per message is determined by a higher layer.

Decomposition of SF-SF and MF-MF communications into type of frame.MF-MF communication behaves slightly differently in the BS and FS of FC.The parts of the message that are not included in the message for DLC reasons are filled in with padding.Any value can be used for padding.Commonly used values are 00, 55, AA, CC, and FF.

Four types of frames are explained.The first N_PCItype is available for immediate judgment upon reception.Each has its own unique parameters.SF.SF_DL.FF.FF_DL.FC.FS.BS.STmin.CF.SN.

CAN multiple frames can send/receive up to 4095 bytes.The parameter N_PCI is at the start of each frame, and there is a mechanism to concatenate the frames well.There are two main transmission methods depending on the number of data to be sent.If the number of data to be sent is 7 bytes or less, single frame transmission is used.If the number of transmitted data is 8 bytes or more, it is a multi-frame transmission.Multi-frame transmission has a mechanism to control the throughput by setting the CF transmission interval and the timing for receiving another FC with FC.

Extended addressing is an extended version of Normal addressing with N_TA added.Mixed addressing has 11bitID and 29bitID versions.The 11bitID (standard ID) version is based on Normal addressing and assumes gateway traversal.The 29bitID (extended ID) version is based on Normal fixed addressing and assumes gateway traversal.

Normal addressing is the simplest addressing format.Normal fixed addressing is the easiest addressing format to define as a specification

There are physical addresses for one-to-one communication and functional addresses for one-to-many communication.Physical and functional addresses are composed of four different addressing formatsThe addressing formats consist of N_AI, N_TAtype, N_TA, N_SA, and N_AE.However, they may or may not be used depending on the addressing format.