In the previous article about HMIs we mentioned what an HMI was. Next, in this article, we are going to show how they are typically used in a PROFINET HMI context. Often, the decision on which protocol to use on the HMI(s) depends on your application requirements and what protocol drivers the HMI supports. So let’s take a look at […]

Network Reference Model

Networks are usually represented by a seven-layer model, the ISO/OSI Reference Model. In the Ethernet world, the seven layers collapse to four. PROFINET uses all four, but not all the time. But we’re getting ahead of ourselves; let’s start at the beginning: the seven layer model. Here’s the seven-layer model with the layers labeled and their functions defined. The layers […]


PROFINET and OPC UA are two common protocols that have some overlap in the automation and process industries, and understanding which protocol to use in a particular part of a network can be confusing. Should a new plant use PROFINET or OPC UA to implement local control loops? What about performance data for an automation cell?  Which protocol is the […]

PROFINET Communication Channels

PROFINET is great at moving information across a network – we never get tired hammering that message home. But exactly how PROFINET moves that information is still a gray area for a lot of users, and deserves a closer look here. To understand how PROFINET moves information, it helps to keep in mind what kind of information it’s moving.  Does […]

PROFINET Supervisors and Supervisor Takeover

In our article on PROFINET Components, we saw that most of the communication in PROFINET flows between Devices and Controllers. Supervisors don’t get much attention because they don’t get involved in production work. However, a PROFINET Supervisor can be a great tool during system commissioning, checkout, and even to troubleshoot when there’s a problem. PROFINET supervisors operate in a similar […]

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.

PROFINET Conformance Classes

In this article, we will cover conformance classes, as they fit into the mandatory features of PROFINET. Every PROFINET device has a defined set of features which are mandatory based on its conformance class. The conformance classes are divided into three categories, class A, B, and C.

Optional PROFINET Features

We often use an age-old catchphrase during our PROFINET one day training classes, “But wait, there’s more!” when we get to the latter part of the day. We’ve found that most engineers and developers don’t realize what the optional PROFINET features are and their purpose.

What is “PROFINET Shared Device”?

PROFINET offers many features which allow for custom-tailored architectures and automation applications.  An overview of these features can be found in our mandatory and optional features articles.  One of these features is “PROFINET Shared Device”, which gives multiple PROFINET IO controllers (PLCs / PACs) access to the same IO device.  You are probably thinking why would we want to do that? And, how could that […]

What is PROFINET I-Device?

Introduction In a recent article, we covered “PROFINET Shared Device”, which gives a device the capability to share IO data with multiple controllers. This time we will discuss I-Device, which operates on the IO controller level. This optional feature allows a controller to be both a device and controller simultaneously, allowing for controller to controller (some might say peer to peer) communications […]

Wireless PROFINET – Architectures

Wireless Architectures When speaking about wireless PROFINET communications for industrial automation, there are a variety of architectures available depending on the application. Overall, there are four main possible architectures: Point to Point Point to multipoint (Infrastructure) Wireless distributed system Mesh  Also, there is an option between Wifi or Bluetooth. PROFINET devices with Wifi/Bluetooth capabilities are readily available by a variety of vendors. […]

What are PROFINET I&M Records?

Identification and Maintenance functions (I&M) allow access to blocks of data kept inside each PROFINET device by use of acyclic read / write record requests. Keeping the data internal to the device allows the control engineer to differentiate similar devices across the network. Things like device name, location in the factory, maintenance  information for this device, etc. can be stored […]