It’s an exciting time for the world of automated production. The recent wave of innovation in
machine learning and artificial intelligence is enabling new digital applications that can fulfill the
promise of Industry 4.0 (or 5.0). For years, the idea of industrial automation networks collecting
process data from machines and sensors for analysis has been advocated as invaluable for
developing insights to improve production — whether to increase efficiency or reduce
greenhouse emissions. The data could be collected, but much of the analysis was missing until
now.
Today, developers are creating smart AI algorithms to analyze minute process data. An
application could, for example, monitor a system’s energy usage, tracking exactly how much
power a production line consumes, and then provide suggestions, such as adjusting the speed
of certain motors on specific machines to lower power consumption without affecting product
output.
Systems with the PROFINET communications protocol, however, will only be able to gain such
benefits if they’re using PROFINET as a network.
When PROFINET isn’t a network
It’s not uncommon for an operational technology (OT) network using PROFINET to be
structured like one or more isolated fieldbus systems. The precursor to PROFINET was
PROFIBUS, a fieldbus communication standard for automation that’s still used today and is
based on master-device interaction — where the master has unidirectional control over all
devices and processes under it. A basic PROFIBUS system is usually set up in a line, while
more advanced configurations that utilize repeaters (like Indu-Sol’s MULTIrep series) can
employ star or tree topologies.
When the industrial automation industry switched over to using PROFINET for OT networks,
many carried over the same philosophy they had used for PROFIBUS. They started building
with PROFINET like it was a fieldbus standard, with each PLC acting as a master to a series of
devices — I/Os, sensors, production machines, etc. This created isolated islands — segmented
sections of devices linked together — within many systems.
For two isolated islands in a fieldbus-designed PROFINET system to exchange data, they need
to be connected with a PN/PN coupler. The coupler works like a normal I/O device in each
segmented section but has to be configured for the specific data transmitted. Each PLC is also
connected to an overlaying supervisory control and data acquisition (SCADA) network to
monitor and manage production. And that framework can be scaled up to hundreds of machines
with hundreds of PLCS.Isolating the different parts of automated production prevents problems from one system
affecting another. But it also hinders access to data for analysis. Applications like the
hypothetical power-usage application from earlier are typically cloud-based and integrated
through the SCADA network, which connects only to master PLCs in a PROFINET-as-fieldbus
situation. And while machines with variable-frequency drives (VFDs) collect many thousands of
operational parameters that can be analyzed for energy efficiency, PLCs don’t require them.
In a fieldbus-like PROFINET system, the SCADA network and overlaying application cannot
directly access data from devices. Necessary information, like data blocks from VFDs, has to be
read from the controllers. Collecting that data and forwarding it requires a PN/PN coupler for
every PLC and specific programming — adding extra costs in time, money, and network loads.
Flexible for future applications without reconfiguration
Thankfully, PROFINET doesn’t have to be used like a fieldbus system. In fact, it’s best
implemented like an IT network.
Using PROFINET as a network can take many different configurations and setups, even ones
with a PLC for each series of devices — with communication between the controllers set up
through the I-Device function. Everything just needs to lead to a single switch that connects to
the SCADA system. This allows applications, through the overlaying SCADA network, to directly
access data from any devices in the OT network, such as VFDs. But it also creates an open
system that’s flexible for future applications without requiring reconfiguration.
Additionally, even though everything is one big network, proper system integration can
prevent issues in one area of the network from affecting another — the only benefit to setting up
separated production lines like isolated fieldbus systems. It also allows integration of OT
network security by enabling network administrators to configure access rights and filter traffic.
That’s essential for meeting updated cybersecurity requirements of the EU’s upcoming Network
and Information Systems Directive 2 — and something a fieldbus system cannot do.
Implementing PROFINET as a Network
Something important to understand and keep in mind is that implementing PROFINET as a
network is extremely difficult after an OT network has been installed. The increased network
load means it needs the right switches and a suitable configuration.
Careful design is required from the beginning. You can license software like Indu-Sol’s PROnet
Plan to simulate network designs and get feedback on where to adjust line depth or add a
switch. Or you can hire an automation engineering firm to design it.
No matter what, ensuring that a system uses PROFINET as a network enables applications,
both current and potential, that can improve any operation with automated production, and
doing so when designing a system at the start is crucial to avoid failures and costly rebuilds later
on.
Have questions or need help designing your PROFINET system as a network? Reach out to us
at Lindh Automation — we can provide everything you need and be the OT network experts you
turn to for support when you’re designing your network.