What is Profinet IO?

Many in the industry are hailing it the 'Next Generation of Industrial Wireless Networks'. But what exactly is PROFINET? and why is gaining so much traction over recent years?

Profinet (Process Field Network) IO is an industrial Ethernet communication protocol based on open TCP/IP and IT standards and developed with an emphasis on Profibus DP similarity.

Some of the advantages of Profinet are;
  • High speed – Ability to deploy thousands of nodes with 1ms updates
  • Broad adoption – Profinet has the largest install base of any Industrial Ethernet and growing rapidly.
  • Advanced diagnostics – PROFINET provides diagnostics at the device, module, and channel levels. Ethernet protocols like Simple Network Management Protocol (SNMP) are used to extract data from Ethernet switches.
  • Community support – Many Profinet experts, active technical committee/working group and collaborative vendor associations.

A Profinet IO system consists of an IO-Controller, IO-Device and IO-Supervisor on Industrial Ethernet network infrastructure. The IO-Controller (usually the main PLC) exchanges input and output signals with field devices.  IO-Devices are distributed field devices such as drives, valves and remote IO.  The IO-Supervisor can be a PC or HMI for configuring and diagnostics of the Profinet IO system.

When adding a new device to a Profinet IO installation, a GSD (General Station Description) file is required.  The GSD file describes the properties of the device for configuration.  In Profinet, the GSD files are XML format that is usually available from the device vendor.

Profinet IO is a name-based protocol.

A variation of Profinet IO is ProfiSafe used in safety systems up to Safety Integrity Level 3.  Profisafe has additional features to increase robustness and suitability.  These features include:
  • Consecutive Numbering
  • Timeout monitoring
  • Source/destination authentication
  • Cyclic redundancy checking (CRC)