In 1979 Modicon (now Schneider Electric, published a new data communication protocol for use with its programmable logic controllers. This protocol, called Modbus, has since become a de facto standard for communication between industrial electronic devices in Europe.
The protocol is simple, openly available and royalty-free.
In a typical deployment, devices are wired together in a network consisting of several Servers/Slaves and one Client/Master, forming a supervisory control and data acquisition (SCADA) system.
In 2004 Schneider Electric transferred the rights of the Modbus protocol to the newly formed Modbus Organization. Handing over the reins for the promotion and development of the Modbus protocol.