Definition of Fieldbus

According to IEC standards of International Electrotechnical Commission and the definition of Fieldbus Foundation FF (Fieidbus Foundation): Fieldbus is a digital, two-way transmission, multi branch communication network connecting intelligent field devices and automation systems. That is to say, the field bus based system takes a single decentralized, digital and intelligent measuring and control equipment as the node of the network, and uses the bus to connect to realize the mutual exchange of information, so that different networks and different field devices can share information, Various operation parameter status information and fault information of the field equipment are transmitted to the control center far away from the field through the bus, and the control center can send various control maintenance configuration commands to the relevant equipment to establish a network with automatic control function.

The node of the field bus is a field device or field instrument, but it is not a traditional single function field instrument, but an intelligent instrument with comprehensive functions. For example, the temperature transmitter not only has the temperature signal conversion and compensation functions, but also has the PID control and calculation functions. The basic functions of the regulating valve are signal driven and executed, and the output characteristic compensation, self validation and self diagnosis functions are also available. Field equipment is interchangeable and interoperable, and bus power supply is intrinsically safe.