Search term
Search term
United States
United States

Industrial communication with PROFINET

PROFINET is more than just a data transmission protocol based on Ethernet technology. It is a standard that establishes high-performance networks and as a result enables efficient automation in smart factories. PROFINET is a must in an industrial environment.

Would you like to find out what data communication with PROFINET looks like, what requirements you need to meet and what you need to keep in mind when selecting a product? We can answer your questions directly in the text below.

Find out more about our PROFINET products

Ethernet and PROFINET – easily explained

PROFINET – Generation and standardisation

The industrial Ethernet system PROFINET was developed by Siemens AG together with the PROFIBUS & PROFINET User Organisation (PNO). This user organisation is now active worldwide and has hundreds of members.

LAPP also plays an active role in the respective working groups.

The PROFINET system is specified internationally in IEC 61918 'Industrial communication networks – Installation of communication networks in industrial premises' for cabling within and between automation islands and/or production islands. The specific infrastructure for PROFINET cabling and connection solutions is standardised in turn in IEC 61784-5-3. This applies for copper-based and fibre optic transmission media and wireless transmission. The 'PROFINET Cabling and Interconnection Technology Guideline' is created by a working group within the PNO. This guideline reflects IEC 61784-5-3.

What benefits does PROFINET offer?

PROFINET combines the benefits of many other protocol standards:


  • 100% Ethernet compatibility
  • Interoperability of PROFINET-compliant components thanks to standardisation
  • Easy integration of Fieldbus systems


  • Flexibility in terms of functionality thanks to the modular design according to conformity classes
  • Easily expandable systems
  • Highly available systems

Safety and maintenance

  • Low maintenance requirement of the network
  • Tried-and-tested safety and diagnostic concepts
  • Scalable real-time communication
  • Components with certification guarantee a high level of system reliability

Which PROFINET variants are available?

The most favoured PROFINET system is PROFINET IO (input/output) from 2006. The PROFINET IO communication system has a modular design and can be set up in various variants. The varying scope of functions enable a corporate network to be designed in a variety of ways. As every automation system sets its own requirements for data transmission, the system operator decides which functionality is required based on so-called conformity classes.

What different Conformance Classes does PROFINET offer?

The possible applications are divided into four conformity classes, which determine, for example, the device types to be used (controller, device, supervisor), the transmission medium used and the type of communication. This ensures that the components of a class are always compatible and meet the necessary requirements. A class supplements the functional scope of the class below with other functionalities.

Note: When selecting your components, make sure they match the Conformance Class you have selected for your automation system.

Conformance ClassTransmission medium usedTypical possible useExamples of scope of function
CC-ACopper conductor
Fibre optic cables
For infrastructure networks and building automation
  • Cyclical real-time communication via RT
  • Acyclic communication via TCP/IP
CC-BCopper conductors and fibre optic cablesFor factory and process automation
  • LLDP neighbourhood detection
  • Network diagnostics via SNMP
  • Redundant communication through two IO controllers
CC-CFor motion control applications
  • ISO-synchronous communication via IRT for clock synchronisation
  • Bandwidth reservation
CC-DFor various applications
  • Scope of functions similar to CC-C, but actions are carried out using time-sensitive networking (TSN) standards

How is the cabling performed in the PROFINET network?

The guideline for PROFINET  specifies the structure as well as the mechanical and electrical properties of copper cables, copper hybrid cables and fibre optic cables that can be used in PROFINET networks. Depending on the type of cable, this also includes requirements regarding:

  • cable marking,
  • core identification colours,
  • shielding type,
  • outer sheath colour,
  • resistance values,
  • attenuation values,
  • frequency ranges,
  • temperature resistance,
  • flame retardance and much more.

PROFINET guideline

This guide describes the passive infrastructure of PROFINET networks within and between the automation islands, as specified in IEC 61918 and IEC 61784-5-3.
Learn more

Which cables are suitable for PROFINET?

Specification for copper cables

Four cable types have been defined for copper cables, for both 2- and 4-pair cables.

Requirements for copper cables (signal transmission only) at a glance:

Cable typeInstallationConductorDesign
Type A
  • for fixed installation
  • No movement after installation
Solid conductor2-pair: AWG22/1
4-pair: min. AWG23/1
Type B
  • for flexible installation
  • occasional flexing of the cable following installation
Flexible stranded conductor, 7-wire2-pair: AWG22/7
4-pair: min. AWG23/7
Type C
  • for special applications
  • e.g. for use in cable chains or applications under torsional load
Solid wire or flexible stranded conductor, up to 19-wire2-pair: AWG22/1 … 19
4-pair: min. AWG24/1 … 19
Type R
  • for robotics
2-pair: AWG22/1 … 19

Fast Connect for PROFINET

Many of our PROFINET data cables have a “Fast Connect” structure with a special inner sheath and a cross separator instead of shielded core pairs (identifiable by FC in the product name). This means that when assembling the data cable with a suitable connector, there is no need for otherwise complicated removal of the pair shielding.

A Fast Connect system is a holistic solution, from the cable to the connector solution to the right tool.

With FC products you save up to 50% of the time when assembling your data cable. It doesn't just sound great. It is.

Find out how uncomplicated the Fast Connect system is and how much faster you can use it to carry out the cable assembly.

HowTo: fast-connect system for Cat. 6a cables and RJ45 connectors

Fibre optic cables specification

For POF, PCF and GOF fibre optic cables, two cable types have been identified.

The requirements for fibre optic cables (optical signal transmission) at a glance:

Cable typeInstallationDesignDiameter of core/sheath
Type B
  • for fixed installation or
  • for flexible installation
  • 2 POF fibres: plastic core and sheath
  • 2 PCF fibres: glass core, plastic sheath
  • 2 GOF fibres: glass core and sheath
  • POF: 980/1000 µm
  • PCF: 200/230 µm
  • GOF singlemode: 9/125 µm
  • GOF multimode: 50/125 µm or 62.5/125 µm
Type C
  • for special applications
  • e.g. for use in cable chains or applications under torsional load

Everything in the green?

Incidentally, the colour of the outer sheath of PROFINET cables is fixed and is a pretty clear identification feature (at least for type A and type B cables): green RAL6018.

It is the preferred choice for type C and type R.


Which plug connectors are suitable for PROFINET?

The PROFINET guideline specifies various plug connector types for the connection technology – both for cabling in protected areas such as in the control cabinet, where a lower protection rating is required, and for cabling in the field with more demanding requirements for dirt and moisture-resistant plug connectors.

Specification for copper connectors

Two standards have been established for copper plug connectors with respect to the data transmission from industrial Ethernet in the PROFINET system – RJ45 and M12.

The plug connector requirements for copper cables at a glance:

Connector typePlug connector classProtection ratingConnector faceTransmission rate
RJ45For protected areasIP 20For 2 and 4-pair cables

up to 100 Mbit/s
up to 10 Gbit/s

M12 D-codedFor applications in the fieldIP 67

For 2-pair cables

up to 100 Mbit/s
M12 X-codedIP 67For 4-pair cablesup to 10 Gbit/s

Ethernet assemblies

With respect to field-configurable plug connectors, the main focus should be on ensuring that the connection process is as easy as possible and performed without the use of special tools where possible. In addition, the plug connectors should be able to connect to as many cables as possible. This means that they cover a broad spectrum of conductor cross-sections and diameters, conductor stranding and external cable diameters.

Specification for fibre optic cable plug connectors

The following standards have been established for optical plug connectors with respect to the data transmission from industrial Ethernet in the PROFINET system.

The plug connector requirements for fibre optic cables at a glance:

To the glass fibre assemblies from LAPP
Connector typePlug connector classProtection ratingFibre type
SC-RJFor protected areasIP 20For POF, PCF
STFor POF, PCF, but only for existing installations

Want more?

From 4-core or 8-core PROFINET cables from the ETHERLINE® brand to fibre optic cables featuring POF, PCF or GOF variants from our HITRONIC® range, the LAPP Group has the right cabling solution for your PROFINET application. Below are some highlights from our online shop:

Copper cables