Wireless Process Control Networks


In order to promote data sharing and analysis in embedded control networks, industrial plants, factories and process automation systems are increasingly deploying information and communications technologies. Despite the severe process control environment, as well as loss of signal propagation and interference with radio frequency (RF), wireless connections provide quick and simple access to a multitude of field tools, reducing network installation expenses and continuing maintenance outlays. This serves as an incentive to adopt industrial wireless networks depending on industry norms such as ISA100.11a, a wireless networking technology standard established by ISA (International Automation Society) and WirelessHART, a wireless sensor networking technology based on the Highway Addressable Remote Transducer Protocol (HART). 

However, wide-ranging acceptance is tentative, as industrial environments differ extensively and process control systems have a variety of critical demands for wireless networking, such as:
  • Long-term durability.
  • Low-cost operation.
  • High reliability in the harsh radio propagation environment.
  • Deterministic transmissions in shared wireless bandwidth.
Wired connections have proved efficient in promoting reliable, point-to-point communication between controller and field tools. Wired links, however, have a difficult restriction - they are unable to meet the increasing demands and future requirements to support adaptive network topology and fast reconfiguration found in new process control systems. 

Instead of setting miles of wires to connect hundreds of field tools, industrial wireless communication networks provide tailored network topology wireless links, enable plug-and-play setup, and provide reduced installation and maintenance costs.

Compared to the demands of conventional Internet data services, the requirements of wireless service quality (QoS) in the process control environment are more stringent. In mobile use cases, these include more extremely reliable transmissions as well as centralized data analytics, tighter message latency, and reduced power consumption.

For more information about wireless networking in the industrial space, contact Analynk Wireless. Visit their website at https://analynk.com, or call them at 614-755-5091.

Hazardous Area Enclosures Facilitate Plant Standards for Wireless Access Points

Hazardous Area Enclosures for Access Point
Hazardous area enclosures for wireless access point.
(Analynk)
There are often conflicts between what is needed and what is desired in many technical endeavors, and the field of industrial process control is no exception. Such a conflict between process engineers and IT managers was created by the incursion and popularity of wireless communication into the field of process measurement and control. It is, of course, a cooperative and friendly conflict, but a condition which may require some incompatible interests to be resolved.

For a number of reasons, compliance with certain norms set for the organization's wider scope and standards is advantageous for the wireless network equipment. Standardization on specific brands or hardware types can have true advantages. The tasks associated with network infrastructure back end management are less complicated when all equipment belongs to the same producer and family of products. Provisioning, which includes initial set-up, long-term management and management of unit losses, is simplified when all units are identical. The same objective is pursued by process technicians and operators in standardizing specific transmitters, valves or other parts that have various facilities throughout a plant.

The AE902-1 is designed to house the Aruba AP-318
The Analynk AE902-1 is designed to house the Aruba AP-318.
The problem occurs when the access point selected by the IT team, with all the latest standards, needs to be installed in a part of the plant categorized as hazardous (owing to the potential for flammable or explosive gases, vapors or dusts that can be ignited). There is a solution, actually a fairly simple one. Use a non-hazardous area access point (as specified or designated by the IT department) and installing it inside an access point enclosure designed for hazardous areas.

Analynk Wireless manufactures enclosures for industrial wireless access points installed in hazardous locations.  Each access point enclosure is provided with agency approved enclosures, antennas, mounting, penetrations, cabling, and power supplies. Their current product offering accommodates a wide range of wireless access point manufacturers including Symbol, Cisco, Meru, Aruba, HP, and Motorola.  Access point and Wi-Fi technology technologies change rapidly. Wireless component lifecycles are relatively short compared to other process equipment. The use of hazardous area access point enclosures provide flexibility and convenience in access point selection and upgrades.

For more information, contact Analynk Wireless by visiting https://analynk.com or by calling 614-755-5091.

Industrial Wireless Systems Radio Propagation Measurements

Radio frequency (RF) propagation measurements were conducted at three facilities representing a cross-section of different classes of industrial environments. Selected sites included a multi-acre transmission assembly factory typical of the automotive industry; a small-sized machine shop primarily engaged in metalworking located on the NIST campus in Gaithersburg; and a steam generation plant located on the NIST campus in Boulder. A spread spectrum correlation sounder was used to take the measurements at a continuum of points throughout the facility by fixing the transmitter and moving the receiver at a constant rate throughout each facility. The data collected from the RF propagation measurements of each site was analyzed. Analysis is based on channel impulse response (CIR) measurements collected during the measurement using equipment developed by the National Institute of Standards and Technology. The results of the analysis include a tabulated summary and detailed exploration of various industry accepted channel metrics such as path loss, delay spread, and K factor. Interpretation of the measurements contributes to an improved understanding of radio frequency propagation in factories and an additional perspective on deploying wireless communication devices within factories.

This technical paper, provided by the National Institute of Standards and Technology (NIST), addresses concerns about the lack of industrial wireless networking reliability, determinism, and security through a multi-phased approach.


Analynk Wireless
(614) 755-5091
https://analynk.com

US Power Grids, Oil and Gas Industries, and Risk of Hacking

A report released in June, from the security firm Dragos, describes a worrisome development by a hacker group named, “Xenotime” and at least two dangerous oil and gas intrusions and ongoing reconnaissance on United States power grids.

Multiple ICS (Industrial Control Sectors) sectors now face the XENOTIME threat; this means individual verticals – such as oil and gas, manufacturing, or electric – cannot ignore threats to other ICS entities because they are not specifically targeted.


The Dragos researchers have termed this threat proliferation as the world’s most dangerous cyberthreat since an event in 2017 where Xenotime had caused a serious operational outage at a crucial site in the Middle East. 

The fact that concerns cybersecurity experts the most is that this hacking attack was a malware that chose to target the facility safety processes (SIS – safety instrumentation system).

For example, when temperatures in a reactor increase to an unsafe level, an SIS will automatically start a cooling process or immediately close a valve to prevent a safety accident. The SIS safety stems are both hardware and software that combine to protect facilities from life threatening accidents.

At this point, no one is sure who is behind Xenotime. Russia has been connected to one of the critical infrastructure attacks in the Ukraine.  That attack was viewed to be the first hacker related power grid outage.

This is a “Cause for Concern” post that was published by Dragos on June 14, 2019

“While none of the electric utility targeting events has resulted in a known, successful intrusion into victim organizations to date, the persistent attempts, and expansion in scope is cause for definite concern. XENOTIME has successfully compromised several oil and gas environments which demonstrates its ability to do so in other verticals. Specifically, XENOTIME remains one of only four threats (along with ELECTRUM, Sandworm, and the entities responsible for Stuxnet) to execute a deliberate disruptive or destructive attack.

XENOTIME is the only known entity to specifically target safety instrumented systems (SIS) for disruptive or destructive purposes. Electric utility environments are significantly different from oil and gas operations in several aspects, but electric operations still have safety and protection equipment that could be targeted with similar tradecraft. XENOTIME expressing consistent, direct interest in electric utility operations is a cause for deep concern given this adversary’s willingness to compromise process safety – and thus integrity – to fulfill its mission.

XENOTIME’s expansion to another industry vertical is emblematic of an increasingly hostile industrial threat landscape. Most observed XENOTIME activity focuses on initial information gathering and access operations necessary for follow-on ICS intrusion operations. As seen in long-running state-sponsored intrusions into US, UK, and other electric infrastructure, entities are increasingly interested in the fundamentals of ICS operations and displaying all the hallmarks associated with information and access acquisition necessary to conduct future attacks. While Dragos sees no evidence at this time indicating that XENOTIME (or any other activity group, such as ELECTRUM or ALLANITE) is capable of executing a prolonged disruptive or destructive event on electric utility operations, observed activity strongly signals adversary interest in meeting the prerequisites for doing so.”

The Argument for Hazardous Access Point Enclosures in the Rapidly Changing World of Wireless Technology

Many companies in the chemical, mining, petrochemical, pulp & paper, power generation, primary metals and pharmaceutical industries now require high-performance Wi-Fi access in potentially explosive environments. These critical applications, whether for device telemetry, network access, site-to-site connectivity, or unified communications, require the highest available Wi-Fi performance inside some of the harshest environments.

There are two ways to design Wi-Fi access points for application deployment inside explosive environments:
  1. Design and build the access point itself to operate directly inside the hazardous environment, without an external enclosure rated for the area.
  2. Use an access point designed for non-hazardous locations, and install it inside an access point enclosure specifically designed for that hazardous classification. 
The first approach is cost effective when underlying technology is slow-to-change, stable, and the pressure to change is years off.

The second approach, using an external access point enclosure, is the best path to take in situations where the underlying technology is changing rapidly.

It only took 10 years for Wi-Fi to move from 802.11n, to 802.11ac Wave 1, to 802.11ac Wave 2. No one wants to buy and install old technology. The thought of implementing a 2007 technology (802.11n for instance) for an application today is silly. Instead, today you would use 802.11ac Wave 1, especially in industrial environments, because of its outstanding multipath performance in the presence of metal. What will you use tomorrow? Who knows. But you should plan accordingly.

Based on typical amortization rates, a customer who wants to stay on top of the latest Wi-Fi technology would update their equipment roughly once every 4 years. If we assume that an access point designed for uncontrolled outdoor environments with wide temperature range operation has a List price of $1,500, and the associated Class 1 Division 2 enclosure Lists for $3,500, and the installation of just the enclosure (excluding access point set-up and commissioning) costs $2,500, then customers will save $4,500 with every turn of access point technology if the enclosure is retained.

If you are working with rapidly changing standards, and technologies such as Wi-Fi whose equipment is constantly upgraded, purchasing and installing a hazardous area enclosure, and swapping out access points as technology changes, is clearly the more economical solution in the long run.

Analynk Wireless, LLC
https://analynk.com
(614) 755-5091

Sensor Network Monitoring: Integrate or Separate?

Analynk AE-902
Analynk AE-902 ATEX Zone 2 and Class 1,
Division 2 Groups A, B, C & D Enclosure
with ISA100a/WirelessHART Gateway and
Aruba AP-318 Access Point
Reprinted from "Built to Blast: Industrial Internet of Things Infrastructure for Hazardous Environments"  by Aruba NetworksFull text white paper can be downloaded here.

Deterministic behavior has long been a requirement for critical control networks in potentially explosive environments, and industrial customers have relied on ATEX Zone 2 or Class 1 Division 2 WirelessHART or ISA100a for years to monitor flow, pressure, temperature, and other wireless sensors. These rudimentary control standards lack advanced cybersecurity features but are very high-speed and low power, making them attractive to oil and gas customers in particular.

Customers are often confused about the pros and cons of purchasing an access point with an integrated 2.4GHz WirelessHART or ISA100a sensor network transceiver, or purchasing a separate control gateway and access point. One of the issues with an integrated access point is that the ideal location for a sensor network antenna can be very different than for a Wi-Fi antenna. The former needs to be within line-of-site of the sensor mesh, while the latter needs to be in line-of-site of roaming client devices and potentially other backhaul access points.

A second reason for remotely locating the sensor network antenna is to avoid interference between the 2.4GHz WirelessHART or ISA100A sensor network and the 2.4GHz Wi-Fi network. WirelessHART uses 2.4GHz 802.15.4-2006 (ZigBee) radios with a channel hopping mesh and time- synchronized messaging. ISA100a also has a single physical layer using 2.4GHz 802.15.4-2006 radios with listen-before-talk operation, short messages, low duty cycle, and adaptive frequency hopping. While both control networks are intended to operate near other wireless network, the reality is that the RF signal degrades with in-band interference, and also interferes with 2.4GHz Wi-Fi channels. Frequency planning, antenna location, and antenna separation must all be considered during the design and implementation phases.

Typically the sensor and Wi-Fi network antennas must be separated by at least one meter, potentially more depending on the frequency of sensor transmissions and the power output and antenna propagation pattern of the Wi-Fi access point. By definition that means one of the systems will require an external antenna and lead-in cable.

Another reason for separating the sensor gateway and Wi-Fi access point was touched on earlier: Wi-Fi is changing at a very fast clip whereas WirelessHART and ISA100a are not. Staying current with technological changes in Wi-Fi requires more frequent updates than do sensor networks, for which change has been very slow. That calculus may start changing after 2021 by which time the new 802.11ax standard could start displacing WirelessHART and ISA100a, leading to hybrid deployments in which new 802.11ax devices have to coexist with WirelessHART and ISA100a. Until that time, separating the sensor gateway from the access point allows RF performance to be optimized for each system while minimizing the impact of RF technology transitions to existing infrastructure.

Technology suppliers have recognized the benefits of building separate sensor gateways for use in potentially explosive environments, and there are multiple vendors for these devices. For example, ArubaEdge technology partners build ATEX Zone 2, Class 1 Division 2 gateways for WirelessHART and ISA100a control networks. These gateways can be connected to a nearby Aruba switch or access point using an Ethernet interface cable up to 100 meters in length, longer if a fiber optics adapter and cable is used. Gateways with a built-in antenna and don’t require a remote antenna or lead-in cable.
If the sensor gateway and Aruba access point must be co-located for cost, convenience, or antenna positioning, an ArubaEdge partner gateway circuit card can be installed in the same explosion-proof housing as the Aruba access point. That design requires an external sensor network antenna and lead-in cable, however, it allows the Wi-Fi access point to be updated as needed without needlessly replacing the sensor gateway.

To learn more, read the entire white paper from Aruba Networks. You can download it from the Analynk website here.