You will find here all the specifications of the industrial Modbus protocol, either used over serial lines or over Ethernet TCP-IP.

Transparent Ready is the Schneider Electric program to connect every Schneider devices and to get transparent access to their data, thanks to the IP and web technologies

IAONA is a collaborative association of more than 100 industrial companies having the objective to develop an industrial Ethernet communication solution.

IDA a sub-group of IAONA developing an industrial Ethernet technology close to the Transparent Ready solution.

The reference consulting group for industrial applications, devices and communication.

CANopen is the open industrial protocol using the CAN bus. 

A Modbus open source library with UML diagrams

Modbus software and tools