The primary fieldbuses used in process control applications are always busy developing technical refinements, adding new capabilities, such as wireless and the ability to run in hazardous settings, and cooperating to increase data translation and ease of use. The latest information on their technologies and activities is available at their websites.
- Actuator Sensor Interface (AS-i) is a mostly device-layer network protocol supported by AS-i International.
- CC-Link is an open-architecture network originally developed by Mitsubishi Electric. It's supported by the CC-Link Partner Association.
- DeviceNet, ControlNet and EtherNet/IP are based on the upper-layer Common Industrial Protocol (CIP), and are supported by ODVA.
- Foundation fieldbus H1 and High-Speed Ethernet (HSE) are supported by the Fieldbus Foundation. Its latest Foundation for Remote Operations Management (ROM) uses HSE over IP as a backhaul network for SCADA systems.
- HART and WirelessHART field communications protocols are supported by the HART Communication Foundation.
- IO-Link is a three-wire, point-to-point I/O connection technology standardized to comply with IEC-61131-9 for communicating with sensors and actuators. It's not a fieldbus, but it performs some of the same networking tasks. It's supported by the IO-Link Steering Committee.
- Modbus is an application-layer messaging protocol that provides client/server communication between devices connected on different types of buses or networks, while its Modbus TCP/IP is its Ethernet-based and Internet-enabled version. It's support by the Modbus Organization.
- OPC is a series of standards specifications for moving real-time data between control devices and interfaces, so it's not a fieldbus either, but it also accomplishes many of the same functions for its users. It's supported by the OPC Foundation.
- Profibus PA, Profinet and Profisafe are supported by Profibus North America and Profibus International.