Sensors are fundamental to industrial control but turning sensors into IIoT systems can be a major challenge

By Rich
Quinnell, editor, Special Projects

Key
components of modern industrial systems are the sensors that feed data to the
controllers, monitors, and other operational technologies running the plant.
Networking of sensors has been in use for years, but the advent of the internet
has expanded both the opportunities and challenges of using sensor systems. The
design opportunities and challenges have also expanded as sensors become part
of the industrial internet of things (IIoT).

Sensors play a variety of roles in the modern
factory. In addition to providing data for process control, they assist in
quality assessment, asset tracking, and even worker safety. The advent of
powerful, cloud-based analytical software and artificial intelligence has also
allowed the use of sensor data to lower production costs through process
optimization and predictive maintenance. And once routed to the internet,
sensor data can be put to a variety of uses from supply management to global
coordination of production resources.

To serve these many purposes, there is a wide
variety of sensor types available, with new and improved versions coming along
continually. Illumination, temperature, motion, position, presence, vision,
force, flow, and chemical composition are among the most common sensor types.
Virtually every type of process or environmental condition has a sensor type
suited to its measurement, available from broad portfolio companies like TE
Connectivity
and specialized providers like Aceinna.

There
is a wide variety of sensor types used in the industry that need connection to
the IoT. (Image: Postscapes)

Traditionally, the information that this
multitude of sensor types provides has remained a local resource, confined to a
single facility or even a single machine. The advent of low-cost, wide-area
connectivity options, however, has opened the door for access to sensor data
from anywhere on the globe. This accessibility has unlocked a huge array of
options for utilizing sensor data and information. One that sparked immediate
and widespread interest is predictive maintenance, wherein remote computers
(somewhere in the cloud) running powerful analytical algorithms use sensor data
to determine the health of machinery in near-real time to identify urgent
maintenance needs before equipment fails. But many other applications are being
identified for leveraging the ability to connect individual industrial sensors
to all of the resources and stakeholders of the world.

Unfortunately, it’s not especially easy to
connect a sensor to the internet and do something useful with the data,
especially if dealing with legacy sensor systems. Industrial sensors use a
variety of protocols for sending their data to their traditional users. The
internet, however, requires data in the TCP/IP format, so there is at least a
protocol conversion required. A hub or gateway may be needed to consolidate and
concentrate the data, especially if many sensors need connectivity. And the
data must have a destination, which means using a cloud service of some kind to
at least store the data for later retrieval and, often, to perform the data
processing.

The connection works both ways, of course, so
connecting the sensor to the web provides an opportunity for remote
configuration and control. It also triggers a need for ensuring the security of
both the data sent and of the control commands coming in (see EE Times: The Day When the
Industrial IoT Gets Hacked
). Authenticating, provisioning, and
monitoring the status of a sensor multitude are additional needs that arise
from connectivity. Thus, an IIoT industrial sensor is actually a complex
collection of hardware and software that spans the gap from the device at the
edge to the services in the cloud. How one goes about establishing this
collection varies considerably by situation. Fortunately, there is also great
variation in the products and services available for designers to apply.

IIot fig 2 -disruptive sensors

Bringing
a sensor system into the IIoT requires a complex ecosystem of hardware and
software. (Image: Disruptive Technologies)

For many developers, legacy sensor systems
will be the IIoT candidates. Industrial equipment typically has a service life
measured in decades, so there is a huge installed sensor base that needs
conversion to internet connectivity. Developers can start by adding smart radio
modules, such as those from Link Labs,
that can tap into existing sensor interfaces and provide the necessary protocol
conversion as well as connectivity. There is a variety of radio networks
available from which to choose as well, including Wi-Fi, Bluetooth, LoRaWAN,
and cellular. Developers connecting legacy systems will then need to select
from among the many cloud service providers and analytics software providers
offering industrial services.

For new system designs, there are several
options available. One, of course, is to use a design approach like that of a
legacy system, starting with the bare sensor. A controller
must be added to provide the sensor interface and data security, along with a
radio to handle the network connectivity. As with the legacy system, designers
must then arrange for the cloud services.

Developers need not work entirely from scratch
when creating a new system, however. Several platform-based approaches have
arisen that simplify combining the sensor, controller, and radio components by
allowing a mix-and-match assembly of compatible components. An example is the M2.COM platform
jointly developed by Arm, Advantech, Bosch Sensortec, Sensirion, and Texas
Instruments. This platform uses a standardized form factor and interfaces to
allow developers to choose a conforming sensor and a wireless module from one
of many different vendors, then simply plug them together, install the
platform’s IoT software agent, and develop their application program to create
a sensor module that can then be used with a variety of cloud platforms.

IIoT fig 3 -M2COM

Assembling
an IIoT sensor system is simpler when using standardized building blocks, such
as with the M2.COM platform. (Image: M2.COM)

Several such cloud platforms are available that were
specifically created to address industrial sensor needs from vendors that do
not make the sensor modules themselves. These include smaller companies such as
Akoom and Kaa IoT Technologies,
more established players such as the PTC ThingWorx platform, and
industry giants such as GE’s
IoT
software and Siemens’
Mindsphere
platforms.

Developers can also choose to forego developing their own smart sensor
module and choose to start with a higher-level building block. Fully integrated
smart sensors, with built-in controller and radio functionality, are available
from companies such as Disruptive
Technologies
, Episensor, and Zenseio. An unusual approach by Axzon (formerly
RFMicro) uses RFID in the sensor module, avoiding the need for wireless
spectrum management but requiring active scanning with a handheld device to
retrieve data and send it to the internet. Advantech, one of the M2.COM
founders, also offers complete smart sensor modules through its Wzzard
family, which includes both LoRA and mesh network approaches.

IIoT fig 4 -Advantech BB Wzzard

A complete IIoT
sensor system, such as this member of the Advantech Wzzard family, integrates
sensor, controller, and wireless link into a ruggedized package. (Image:
Advantech)

What all of these integrated smart sensor
offerings have in common, though, is that the vendors are not just providing
smart connected sensors. They also offer gateways and software to securely get
the data all the way to the cloud in a form compatible with cloud platform
service providers. This relieves designers of all the hardware effort needed to
establish an IIoT sensor system if their sensing needs are met by one of the
available modules.

The system integration needed to marry even a
smart sensor system with the many software services needed to ensure security
and to manage and extract actionable intelligence from IIoT sensor systems is
still significant. To relieve designers of this burden, numerous companies are
now offering complete end-to-end packages, from the sensor through cloud device
management and analytics services. Some are smaller offerings, like the IoTini
I2OT family, which primarily offers environmental sensors as well as universal
analog and digital sensor interfaces. QBurst
focuses its sensor on applications for monitoring rather than industrial
control.

But there are also some major players in the
edge-through-cloud IIoT sensor system market. These companies typically offer a
variety of sensors and configurations, often with custom design support as
well. ABB, for instance, offers
end-to-end and closed-loop systems through its ABB Ability program. Bosch-Sensortec
offers several universal sensor modules and supports the M2.COM
development approach. Rockwell Automation’s Allen-Bradley division also offers general-purpose sensors as well as more
specialized pressure and image sensors, leveraging its IO-Link radio
technology.

IIoT fig 5 -Versasense sensors

Whether
connecting legacy sensor systems to the internet or creating new systems,
designers have a multitude of choices for IIoT sensor systems. (Image:
Versasense)

Closing the loop is Versasense.
The company’s many offerings include complete edge-to-cloud sensor systems as
well as gateway devices and cloud services. It also offers devices that allow
connection to legacy sensors, translating their protocols to bring them from
factory networks into the IIoT. These legacy connections can then utilize the
cloud management and analytics services that form part of the Versasense
family.

However it is done, gathering data and getting
it into the cloud, where it can be turned into information and actionable
intelligence, has tremendous potential to help optimize and cost-reduce
industrial operation. Developers need to choose the approach that best suits
their specific needs from among the many that are available.


Richard Quinnell is editor for special projects at AspenCore.

This article is part of the AspenCore
Special Project on industrial IoT sensors. Check out these other
articles from the Industrial IoT Project.

The
role of Sensors in the industrial IoT (IIoT)

Deploying
IIoT sensors in the Smart Factory

Jumping
into Industry 4.0 with Predictive Maintenance Solutions

For more insight into sensors, check
out these other articles across the AspenCore network.

7
Controllers for Internet of Things

Intelligent,
IO-Link connected sensors underpin the Industrial Internet of Things

Industrial sensors and control — The basics — Parts IIIIIIIVVVIVII