汽车上采集的J1939数据，辅助你了解J1939的协议，并且有部分说明，如果你能全解释出来，说明你吃透了J1939协议，很有用哦-J1939 data collected on the car, you know the J1939 protocol assistance, and there are some instructions, if you can explain it all to show that you thoroughly understand the J1939 prot