ControlNet is an open industrial network protocol for industrial automation applications, also known as a fieldbus. ControlNet was earlier supported by ControlNet International, but in 2008 support and management of ControlNet was transferred to ODVA, which now manages all protocols in the Common Industrial Protocol family.
Features which set ControlNet apart from other fieldbuses include the built-in support for fully redundant cables and the fact that communication on ControlNet can be strictly scheduled and highly deterministic. Due to the unique physical layer, common network sniffers such as Wireshark cannot be used to sniff ControlNet packets. Rockwell Automation provides ControlNet Traffic Analyzer software to sniff and analyze ControlNet packets.