In the industrial world, the MODBUS protocol is largely supported by machines and installations in general. This protocol originally published by Modicon (now Schneider Electric) is the market standard. The success of MODBUS comes from the fact that it is simple to implement, open and free, and that it has been developed with industrial problems as a guide.
It makes it possible to connect industrial objects through a network, on the basis of the “Master” – “Slave” principle. A supervision software is Master and can thus interrogate or manipulate different machines, installations, devices, and more specifically to interact with notions like “coil“, “discreet input“, “input register” or “holding register“. Clearly, it is possible to modify the configurations / parameters of an installation connected in MODBUS, as well as to recover different measured elements (temperature, pressure level, energy consumed, units processed …).
There are basically 2 methods for connecting to MODBUS installations. Either based on a serial bus (RS485). This is called MODBUS RTU. Either via Ethernet. This is called MODBUS TCP.