Modbus协议规范。包括TCP和RTU，里面写的很详细，我就通过阅读它完成了Modbus-Tcp组件的编写.包括01,03,05,06,15,16等常用Modbus指令的操作。-Modbus protocol specification. Including TCP and RTU, which is written in great detail, by reading it has completed the preparation of the Modbus-Tcp component, including the operation of of 01,03,05,06,15,16 other commonly used Modbus instruction.