PROFINET Basics


What is PROFINET?

PROFINET is a mechanism to exchange data between controllers and devices. Controllers could be PLCs, DCSs, or PACs. (Programmable Logic Controllers, Distributed Control Systems, or Programmable Automation Controllers.) Devices could be I/O blocks, vision systems, RFID readers, drives, process instruments, proxies, or even other controllers. PROFINET exchanges data quickly and deterministically. Required speeds vary depending on the application; process instruments […]


Physical Layer Requirements

The physical layer requirements for PROFINET are simple: PROFINET lays directly on top of standard IEEE 802 Ethernet. Any PROFINET device can be placed on a standard Ethernet network in a home or an office, and it will communicate just the same as it would on the factory floor.


Components: Device, Controller, Supervisor

A PROFINET network can be a complex collection of stations, from digital I/O devices to pneumatic actuators to laser scanners… the list seems endless and grows every day. But within that complex network, all PROFINET components operate within three different roles. They can be either Devices, Controllers, or Supervisors.


PROFINET GSD File Basics

What is a GSD File? A PROFINET General Station Description (GSD) file is a description of an IO device provided by the device manufacturer. The contents of the GSD consists of configuration information, parameters, modules, diagnostic and alarms, and vendor and device identification. To discuss the latter two in a little more detail, the vendor identification (vendor ID) is a number […]


Real Time Classes

PROFINET has class, in fact, many classes: Conformance Classes, Real Time classes, media redundancy classes, and even more class(es). This article covers Real Time Classes and how PROFINET works.


Isochronous Real-Time (IRT) Communication

When you mention the words “real-time” and “Ethernet” in the same sentence, let alone next to each other, you get some incredulous looks.  Ethernet, by definition, is an open network that allows anyone to transmit at any time – making it a probabilistic transmission medium.  Unless there’s abnormally high bandwidth utilization, Ethernet is built on the assumption that nodes will probably […]


DCP – Discovery and Configuration Protocol

PROFINET DCP is part of the protocol suite and stands for “Discovery and basic Configuration Protocol”. It is used by the engineering tool and controller to discover devices, identify device information, and configure device settings such as PROFINET device name and IP address on a PROFINET network.


PROFINET DCP and DHCP

We often get the question: Why doesn’t PROFINET use Dynamic Host Configuration Protocol (DHCP) for IP address assignment as DCHP is used extensively in the office? Answer: DHCP could be used, optionally, but there are some differences you should know between DHCP and PROFINET DCP.


LLDP in PROFINET

Unlike other competitor networks, all PROFINET devices support Link Layer Discovery Protocol (LLDP) which is defined in IEEE standard 802.1AB.   There are multiple reasons for LLDP support.  The first is to be able to discover, check, and maintain the topology of the PROFINET network and obtain diagnostics if something changes.  The second is for easy device commissioning when setting up […]


PROFINET Device Names

What’s the MAC address of the device you are viewing this from? The IP Address? What’s your name? The easiest of all those to remember is your name, mine is PNC for short. PROFINET device names are used for the same reasons.


PROFINET Naming Convention

The number one rule-of-thumb, which you should never forget when commissioning a PROFINET system: make sure to assign the device name from your engineering tool (or setup auto commissioning). Here is the PROFINET Naming Convention list to help you out.


PROFINET Naming Conversions

In our last article on PROFINET naming conventions, we gave you the basis naming conventions and the network representation of the PROFINET device names.  However it should be pointed out that PROFINET devices can be named just about anything in the engineering tools as the name will be converted automatically by the PROFINET tool into a network representative format using PROFINET naming conversions.  […]