wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

12-4 Industrial Communication Systems
for the extension of data collection into areas either too remote or too hostile to be viable for wired
instrumentation. One of the main motivational factors for going wireless is therefore to provide a costefficient
way of improving production optimization by adding additional measurement points to a production
site. The new measurement points can either be permanent or of a temporary nature, due to the
low installation cost and the added flexibility and scalability of the WSN.
Another benefit of wireless transmitters compared to wired ones is that cables can be cut or damaged
by moving machines and vehicles, by human operators, or by the environment itself in the shape
of extreme weather conditions, vibrations and strain, junction corrosion, and exposure to chemicals or
other fluids.
12.4 Industrial Applications and Requirements
WSNs are currently considered primarily for noncritical monitoring and control applications.
The WSN technology is still not mature enough to be a viable candidate for critical monitoring
applications or closed-loop control [SMCN06]. However, even for noncritical monitoring and
control-related usage, there is a multitude of applications, including condition and performance
monitoring, surveillance and monitoring, environmental monitoring, process control, emergency
management, and asset and personnel tracking and monitoring. For some of these applications,
the wireless transmitter will function either as a replacement or extension of the traditional wired
fieldbus-based (i.e., FOUNDATION Fieldbus [IEC61158], PROFIBUS [IEC61158], and HART
[HART]) transmitters. In this setting, the wireless transmitters can also function as an extension
of a wired network.
In order for WSNs to be viable for industrial applications, they have to fulfill a set of requirements.
In [PDA08], the general technical requirements for the use of WSN technology in both onshore and offshore
facilities in the oil and gas industry have been identified. These requirements should be applicable
to other industries as well, since the oil and gas industry can be considered as one of the most demanding
industries, representing the strictest requirements regarding technology robustness and reliability.
Note that some requirements are application dependent and will vary depending on the individual
usage scenarios.
12.4.1 Standardized Solutions
By using standardized, open communication protocols over proprietary protocols, the industry is provided
with the flexibility and freedom to choose between multiple suppliers and still have guaranteed
interoperability. In addition, a standardized solution usually has a longer life span with respect to
component availability and support compared to their proprietary counterparts as well as the added
benefit of not being committed to a single vendor. When it comes to replacing a broken transmitter in a
network, the new transmitter needs to be of the same standard, but with guaranteed interoperability it
does not necessarily have to come from the same provider.
Section 12.5 provides a survey and evaluation of international WSN standards which are suitable for
industrial applications.
12.4.2 reliable Network Performance
The most basic requirement on a WSN is that it should have a reliable and quantifiable network performance.
As the performance of a wireless network is more susceptible to changes in the local environment,
such as antenna adjustments, moving personnel or equipment, and fluctuations in temperature
and humidity, compared to a wired network, it is important to be able to quantify the expected operational
performance of the wireless network. For most applications, it is desirable to have the network
reliability close to 100%, i.e., there should be practically no loss of sensor data.
© 2011 by Taylor and Francis Group, LLC