"Modbus Protocol is a messaging structure developed by Modicon in 1979. It is used to establish master-slave/client-server communication between intelligent devices. It is a de facto standard, truly open and the most widely used network protocol in the industrial manufacturing environment. It has been implemented by hundreds of vendors on thousands of different devices to transfer discrete/analog I/O and register data between control devices. It's a lingua franca or common denominator between different manufacturers. One report called it the "de facto standard in multi-vendor integration". Industry analysts have reported over 7 million Modbus nodes in North America and Europe alone." From: http://www.modbus.org/faq.php
This brief article is just the tip of the iceberg for the Modbus protocol, and any discussion of Process Control, SCADA systems and security.
Adrien de Beaupre
Oct 22nd 2009
1 decade ago