参考博客
https://blog.csdn.net/MuscleBaBa_Chang/article/details/82957002?utm_medium=distribute.pc_aggpage_search_result.none-task-blog-2~all~first_rank_v2~rank_v25-4-82957002.nonecase&utm_term=modbusscan%E4%BD%BF%E7%94%A8%E8%AF%B4%E6%98%8E&spm=1000.2123.3001.4430
此为主站
打开从站modbus slave
设置与主站相同的功能码
用wireshark捕获流量数据
主站的Length长度和从站的额寄存器或线圈数量相同
