Category Archives: Fieldbus Protocols

What is Fieldbus? Learn about PROFIBUS, Foundation Fieldbus, and HART protocols used in oil, gas, and process automation industries.

PROFIBUS vs PROFINET: Key Differences Explained

PROFIBUS is a serial fieldbus. PROFINET is Industrial Ethernet. They share the same organization, the same application profiles, and the same GSD/GSDML device description concept — but everything underneath is different. PROFIBUS DP (CP 3/1 in IEC 61784-1) runs on RS-485 at up to 12 Mbit/s. PROFINET (CP 3/4, 3/5, 3/6 in IEC 61784-2) runs on IEEE 802.3… Read More »

IEC 61158 Parts 5 & 6 Explained: Application Layer & Protocol Machines

The application layer is where industrial communication becomes meaningful. If: Then the application layer defines what those frames actually mean. IEC 61158 Parts 5 and 6 define: This layer enables: This article explains the IEC 61158 application layer in clear, practical terms for automation engineers and protocol developers. 1. What the Application Layer Does The application layer (Layer… Read More »

IEC 61158 Data-Link Layer Guide (Parts 3 & 4 Explained)

The data-link layer is where deterministic industrial communication truly begins. If: Then IEC 61158 Parts 3 and 4 define how frames are structured, timed, and controlled. The data-link layer: This article explains the IEC 61158 data-link layer in practical engineering terms. 1. What the Data-Link Layer Does The data-link layer (Layer 2 of OSI) is responsible for: It… Read More »

IEC 61158-2 Physical Layer Explained: Media, Signaling & Deterministic Communication

IEC 61158-2 defines the physical layer specification for industrial fieldbus communication systems. It establishes the electrical, optical, and timing rules that allow deterministic data transmission between industrial devices. While IEC 61158-1 defines the architecture of the standard,IEC 61158-2 defines how bits physically travel across copper and fiber media. This article explains the IEC 61158-2 physical layer in clear,… Read More »