关键词: CKS32, CAN总线, IAP, 断点重传, 多节点

Abstract: A remote online upgrade scheme based on controller area network (CAN) bus and in-application programming (IAP) technology is proposed, which can solve the problem of inconvenient firmware update in distributed control system and successfully realize single-node and multi-node synchronous online upgrade. In this scheme, the PC host computer is designed in PyQt5 C++, which realizes the communication and interaction with each CKS32 CAN slave node through the USB to CAN interface. The CKS32 CAN slave node divides the on-chip Flash into four segments and loads the code by time based on the characteristics of IAP technology. In order to avoid abnormal interruptions and error codes during data transmission, breakpoint retransmission, counting and CRC16-MODBUS checksum mechanism are added to improve the safety and efficiency of the upgrade. After testing, the total upgrade time in the distributed system is shortened, the upgrade success rate is more than 95%, and even if the CAN slave node fails to upgrade, it can still report the result and run according to the previous state.

Key words: CKS32, CAN bus, IAP, breakpoint retransmission, multi-node