Can PROFINET and Ethernet Employ the Same Switch?

Switches are crucial components in industrial networks. They are commonly implemented in PROFINET configurations to deploy various topology options (i.e., tree, star, line, ring). But are those switches able to handle PROFINET telegrams and other Ethernet traffic?

PROFINET can coexist with other Ethernet-based protocols in the same network and share network infrastructure, such as switches and cabling. PROFINET is based on standard unmodified Ethernet; the network is not restricted to just PROFINET telegrams.

The following section expands on switches in PROFINET networks.

PROFINET and Ethernet on the Same Switch

PROFINET is an Ethernet-based solution. It is a communication protocol to exchange data between controllers (i.e., PLCs, PACs, DCS) and devices (i.e., IO blocks, sensors, actuators). It sits on Layer 7 of the ISO/OSI Model. It defines cyclic and acyclic communication, such as diagnostics, functional safety, and alarms.

PROFINET is based on standard Ethernet for its communication medium. Having Ethernet on the factory floor brings many benefits, such as high bandwidth, large message size, flexible topology options, and extensive address space.

If you encounter a PROFINET network, you will notice the Ethernet components, such as cables, switches, and connectors linking PROFINET devices.

Ethernet switches in a PROFINET configuration switch all Ethernet traffic, regardless of their application. The Ethernet cables and connectors linking the devices can also transmit Ethernet traffic from various sources (not only PROFINET).

PROFINET is compatible with standard Ethernet switches that fulfill the minimum requirements of 100 Mbit/s, full-duplex transmission. Nowadays, most off-the-shelf switches fulfill both criteria, but some may offer substantial benefits and additional features. For example, some switches can provide several advantages, such as user option selection based on a Command Line Interface (CLI) or Graphical User Interface (GUI), and extensive diagnostics capabilities.

Employing PROFINET + Other Ethernet Protocols

Besides PROFINET, you can employ other Ethernet-based protocols to complement your network. But how? And which protocols?

Since PROFINET is based on standard unmodified Ethernet, the network is not restricted to just PROFINET. You can employ MQTT, SNMP, OPC UA, or HTTP to send data vertically, manage network diagnostics, or interface with web servers.

Those four protocols are not the only ones you can implement in a PROFINET project. Any Ethernet-based protocol can coexist with PROFINET and share the same network infrastructure.

Learn more about switches in PROFINET projects with this short and informative white paper:

Ethernet Switches: Managed vs. Unmanaged for PROFINET