The Modbus protocol was developed by Modicon, now a brand of Schneider Electric.
It was originally designed in 1979 for use with its programmable logic controllers (PLCs) in industrial
applications.
Modbus is a serial communications protocol that has become a de facto standard communication
protocol and is now commonly used to connect industrial electronic devices. The main reasons for its
use are its simplicity and the fact that it is open-source, which allows manufacturers to build their
own implementations of the standard.
Reference
"Modbus Protocol Reference Guide," Modicon, Inc., 1979.
"A Guide to the Modbus Protocol," Schneider Electric.
