Mitsubishi FX PLC free port RS command realizes Modbus Communication

Early controllers （PLC） Some don't MODBUS Communication command , either CRC Verification instruction , So we are writing this kind of controller MODBUS Communication time MODBUS Data frames and CRC Check codes need to be calculated by ourselves . In this blog post, we will talk about using RS Instruction completion external MODBUS Communication function , Limited to my level and ability , Mistakes and deficiencies are inevitable in the text , Sincerely welcome everyone to correct and criticize , At the same time, thank you for your attention and subscription .

Siemens MODBUS Communications , See the following blog post ：

SMART200PLC MODBUS Communication topics _RXXW_Dor The blog of -CSDN Blog _plc Of modbus Communication program MODBUS yes OSI Model number 7 Application layer message transmission protocol on layer , It provides clients... Between devices connected to different types of buses or networks / Server communication . since 1979 Since the emergence of the de facto standard for industrial serial links ,MODBUS Enable thousands of automation devices to communicate . at present , Continue to add to the simple and elegant MODBUS Structural support . Internet organizations can make TCP/IP Reserved system port on stack 502 visit MODBUS.MODBUS It's a request / Reply protocol , And provide the services specified by the function code .MODBUS Function code is MODBUS request / The reply PDU The elements of ....https://blog.csdn.net/m0