Tech Briefs Magazine - April 2022 - MD-8

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Figure 3: An example of Node-RED being used to control a lamp through analog and digital I/O. (Photo: Node-RED)
world. Edge controller manufacturers
have leveraged this experience to provide
the same level of security at the core.
This starts with relatively simple measures,
such as not using standard passwords,
enforcing user accounts that have
tiered access rights, and assuming there
will always be an unwanted actor trying
to gain access to the system.
Security extends all the way to the
heart of the system. The operating system
used for IT-based activity will be entirely
separate from the real-time operating
system used for control. The key
here is maintaining the modern equivalent
of the venerable air gap while still
allowing both sides of the system to exchange
data. This is typically achieved
using a protocol that has security baked
into it, such as Open Platform
Communications Unified Architecture
(OPC UA) and MQTT.
Battle-proven
security
techniques,
such as firewalls, will also be deeply embedded
into the system and not an optional
extra. In conjunction with this, an
edge controller will partition communication
ports to support trusted and nontrusted
parts of the network.
Hardware for Edge Controllers
With greater emphasis on the embedded
software running inside, edge controllers
require processors that can handle
the demand. In fact, it is likely that
the processors used will have multiple
processing cores and follow a heteroge8
neous
multicore structure. This contrasts
with PLCs and even PACs, which
are often based on a single-core highend
microcontroller.
In practice, the processing solution
used will have two or even four Arm
Cortex-A class processors supported by a
Cortex-M class core. This combination
provides a flexible approach to system
architectures. Many Cortex-M cores are
now able to run a real-time operating
system and provide the control functionality.
The A-class processors are designed
for large Linux-based operating systems,
which typically come with all the drivers
and APIs needed to implement highspeed
secure networking.
For single-core solutions, virtualization
may be used to partition the two
domains. Virtualization software and hypervisors
are now used extensively to
create multiple and virtually separate
operating environments using a single
processor.
The three RZ/N1 groups of singleand
multi-core processors from Renesas
are a good example of how this is being
implemented. The devices
in
these
groups are based on the Arm Cortex-A7
and Cortex-M3 cores. They provide
five-port Ethernet switch functionality
and support for various Ethernet-based
protocols commonly used in industrial
applications.
The STM32MP1 is another example
from STMicroelectronics. This represents
ST's first microprocessor solution,
and it integrates one or two Arm
Cortex-A7 cores with an Arm Cortex-M4.
Secure Connectivity
The focus of manufacturers bringing
edge controllers to market is industrial,
which is indicative of the massive change
happening in this sector right now. The
Industrial IoT is fundamental to Industry
4.0, and edge controllers are a response to
the demand for more secure connectivity
and functionality in the control domain.
However, other areas are also going
through a similar revolution. The IoT
does not discriminate and digital transformation
is not restricted to Industry
4.0. Edge controllers, as described here,
are geared toward bringing the industrial
sector into the IoT, but the term
" industrial " is broad. It is not limited to
manufacturing or automation in a manufacturing
environment.
Other markets, such as medical, commercial,
and social are also developing.
Smart hospitals, smart buildings, and
smart cities all need a similar mix of operation
and information technology.
This will propel the concept of a secure
edge controller into new application
areas. The inherent flexibility and capability
of these devices, and the performance
offered by the processors that
power them will help shape " World 4.0. "
This article was written by Philip Ling,
Senior Technology Writer, Avnet Inc.
(Phoenix, AZ). For more information, visit
http://info.hotims.com/82320-280.
Motion Design, April 2022
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Tech Briefs Magazine - April 2022

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