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.

Business Case for Industrial Wireless

One of the key enablers of factory automation is the availability of wireless radio frequency devices. Some applications of radio frequency devices include process control, oil and gas refineries, pharmaceuticals, food and beverage, autonomous guided vehicles (AGVs) control, slotted microwave guides, pendants to control cranes and machine tools, active and passive radio frequency identifier (RFID) for tracking parts, tools and consumables, wireless barcode readers, remote sensing of critical process parameters, mobile telephony, door openers, emergency communication, and general factory Wi-Fi for internet connectivity. In addition, devices not directly associated with the manufacturing process such as microwave ovens and mobile telephone hot spots must be included when designing a factory wireless system. As useful as wireless communications is, it must be recognized that spectrum is limited and there must be judicious choices about when it should be used, and when wired connections are preferable.

In general terms, wireless (as with any upgrade to a factory or enterprise system) should satisfy a requirement related to quality, reliability, efficiency, safety, regulation, or environment as shown in Table 4. The requirements pertain to the business enterprise which in the case of a manufacturing operation means the plant or factory. A wireless deployment should be designed to satisfy one of the key business concerns listed.

Table 4. Purposes for initiating a wireless systems deployment

• Functionality - Is wireless required to achieve an aspect of function within the factory operation? For example, does the factory require a mobility to achieve a goal?
• Reliability - Is reliability of the production line improved? The ability to manufacture products, parts or assemblies which conform to the engineering definition, and can demonstrate conformity.
• Safety - Are people or equipment made safer? The ability of employees to perform their jobs free from recognized hazards including falls, hazardous energy, confined space, ergonomics, and hazardous materials, and being able to demonstrate compliance with all safety regulations.
• Efficiency - The ability to meet target costs and continue forever to reduce unit production costs.
• Quality - The ability to manufacture parts and assemblies which conform to the engineering definition, and be able to demonstrate conformity.
• Environment - The ability to demonstrate compliance with applicable government regulations at the city, county, state, and federal level.

Reprinted from "Guide to Industrial Wireless Systems Deployments" by the National Institute of Standards and Technology. Get your copy here.

Updated and Expanded Wireless Equipment Enclosure Options

Analynk customizes wireless equipment enclosures to
provided customers ready to run solutions.

Analynk offers customizing and fabrication of wireless equipment enclosures to meet every customer requirement. Combining their industrial wireless transmitters, receivers, repeaters, antennas, and other components into a fully assembled package, Analynk can save customers time and cost with a complete and ready to run solution for establishing wireless process instrument connections across almost any distance.

The company recently updated the documented offering for enclosure options. If you have the old document, you should replace it with the newest version.

Share your industrial wireless connection requirements and challenges with the experts at Analynk. Combining your own knowledge and experience with their application expertise will deliver an effective solution.

Pyrometers

Pyrometers permit temperature measurement without contact

Non-contact measurement technology allows process operators and technicians to evaluate the temperature of process materials, machinery, or piping by measuring their electromagnetic radiation. Through inferential calculation and one or more radiation measurements, specialized instruments can determine temperature without contacting the subject material or surface. While the concept of non-contact measurement technology has existed for many years, more recent advancements in non-contact temperature sensing and the evolution of the pyrometer have allowed temperature measurement at a distance to become popular throughout industrial process operations.

Pyrometers can commonly concentrate light from an object onto a temperature sensing element. The sensed elevation in temperature is proportional to the infrared optical energy. Different instruments may have varying arrangements of concentrating lenses and sensors, but the operating principle is the same. The physical law behind the pyrometer’s operating principle operates on an exponential mathematical basis that is non-linear. This results in one of the limitations of the pyrometer. A single pyrometer can only, with high accuracy, deliver a comparatively narrow range of target temperature. If the need for accuracy is reduced, the applicable temperature range widens. Innovative manufacturers have developed instruments with technology and features overcoming many of the limitations imposed by the physics, delivering instruments with accuracy and applicable temperature range usable in a wide array of applications.

One of the advantages to using a non-contact pyrometer is that their calibration is independent of the distance between the sensor and the object being evaluated. This phenomenon is due to the fact pyrometers have a field of view and can be filled with the target object in a way independent of distance. While the radiation emanating from the target object may be decreasing, the field of view of the pyrometer is measuring a greater portion of the object which is proportional to the amount of radiation being lost, essentially canceling out the distance and allowing the pyrometer to provide useful output. An example of a practical application of a pyrometer in industry would be its use to check the temperature of a ventilation system in the HVAC field.

Share your temperature measurement requirements and challenges with process instrumentation specialists. Their product application expertise will combine with your own process knowledge and experience to produce an effective solution.

Analynk Wireless manufactures wireless connectivity solutions for industrial applications and process control. Making cable free connections among process control equipment and instruments, across the room, across the property, across the globe.

Industrial Wireless as Mainstream Connection Method For Process Measurement

Establishing wireless connections for process control operations
is simple, effective, and inexpensive

Wireless connections to process instrumentation has evolved to a point where it is uncomplicated and inexpensive. Many facilities rely on wireless connections, either via a network (wifi) or point to point communications. The benefits of wireless are well known to those already among users of the technology.

• Safety: Wireless connections can reduce personnel exposure to hazardous environments or situations that previously required human intervention or a manual gauge or instrument reading.
• Easy Scale-up: Adding points on a network is generally a simple incremental process.
• Operational Advantage: When deployed to replace manual instrument or gauge readings, real time data for diagnostics and efficiency measurements are now available. Information that is more accurate, timely, and consistent will produce better results.
• Installation Savings: Installation of wireless connected assets has been reported to be up to 10 times less expensive than wired installation. The reduced space and planning for cables and conduit can make what were once complex and time consuming operations much quicker and easier.
• Mobility: Wireless technology allows for real time connections to mobile platforms. Whether within a plant, on the road, or on the high seas, there are wireless products that can make the connection.
• Distance: Don't just think WiFi, think radio, think satellite, think cellular. Connections can be established across very long distances using standard products from the industry.
• Conversion of Legacy Devices: Many existing in-place devices can have their wired connections replaced with a wireless version. This accommodates a staged transition from wired to wireless in facility.

The transmission is accomplished in either the 900 MHz or 2.4 GHz band, delivering adequate range and power for most facility-wide applications. Obstructions can be overcome with the use of a strategically located repeater. Properly planned and configured, there are few limits to the distance a wireless connection can span.

Point to point wireless connections between, for example, a temperature transmitter and a recorder are easy to create. Most process sensors have very small power requirements, as do the Analynk transmission units. Power, if line voltage is not available at the location, can be provided by batteries, or combination of battery and photovoltaic. The 4-20 mA signal from the temperature transmitter serves as the input signal to the wireless transmitter. The analog signal is converted to a digital value and encrypted prior to transmission. A receiver at the recorder decrypts the digital signal and converts it back to a 4-20 mA analog output that serves as the input signal to the recorder. Wireless transmitter and receiver must be set to the same channel, but otherwise, the equipment handles all the work. If you can find your way around a smart phone, you can make a wireless point to point process connection.

There are likely many applications going unfulfilled because the cost or feasibility of making a wired connection is holding the project back. Reconsider the project using industrial wireless technology and you may find that the project becomes an attractive prospect.

Analynk Wireless designs and manufactures wireless communication equipment and systems for use in commercial and industrial settings. Share your connectivity challenges with the experts at Analynk, combining your own process knowledge and experience with their wireless communications expertise to develop an effective solution.

Protect Process Instrumentation From These Five Sources of Damage

Device protection contributes to process success 

The performance of every process is critical to something or someone. Keeping a process operating within specification requires measurement, and it requires some element of control. The devices we use to measure process variables, while necessary and critical in their own right, are also a possible source of failure for the process itself. Lose the output of your process instrumentation and you can incur substantial consequences ranging from minor to near catastrophic.

Just as your PLC or other master control system emulates decision patterns regarding the process, the measurement instrumentation functions as the sensory input array to that decision making device. Careful consideration when designing the instrumentation layout, as well as reviewing these five common sense recommendations will help you avoid instrument and process downtime.

Process generated extremes can make your device fail.

Search and plan for potential vibration, shock, temperature, pressure, or other excursions from the normal operating range that might result from normal or unexpected operation of the process equipment. Develop knowledge about what the possible process conditions might be, given the capabilities of the installed process machinery. Consult with instrument vendors about protective devices that can be installed to provide additional layers of protection for valuable instruments. Often, the protective devices are simple and relatively inexpensive.

Don't forget about the weather.

Certainly, if you have any part of the process installed outdoors, you need to be familiar with the range of possible weather conditions. Weather data is available for almost anywhere in the world, certainly in the developed world. Find out what the most extreme conditions have been at the installation site....ever. Planning and designing for improbable conditions, even adding a little headroom, can keep your process up when others may be down.
Keep in mind, also, that outdoor conditions can impact indoor conditions in buildings without climate control systems that maintain a steady state. This can be especially important when considering moisture content of the indoor air and potential for condensate to accumulate on instrument housings and electrical components. Extreme conditions of condensing atmospheric moisture can produce dripping water.

Know the security exposure of your devices.

With the prevalence of networked devices, consideration of who might commit acts of malice against the process or its stakeholders, and how they might go about it, should be an element of all project designs. A real or virtual intruder's ability to impact process operation through its measuring devices should be well understood. With that understanding, barriers can be put in place to detect or prevent any occurrences.

Physical contact hazards

Strike a balance between convenience and safety for measurement instrumentation. Access for calibration, maintenance, or observation are needed, but avoiding placement of devices in areas of human traffic can deliver good returns by reducing the probability of damage to the instruments. Everybody is trained, everybody is careful, but uncontrolled carts, dropped tools and boxes, and a host of other unexpected mishaps do happen from time to time, with the power to inject disorder into your world. Consider guards and physical barriers as additional layers of insurance.

Know moisture.

Electronics must be protected from harmful effects of moisture. Where there is air, there is usually moisture. Certain conditions related to weather or process operation may result in moisture laden air that can enter device enclosures. Guarding against the formation of condensate on electronics, and providing for the automatic discharge of any accumulated liquid is essential to avoiding failure. Many instrument enclosures are provided with a means to discharge moisture. Make sure installation instructions are followed and alterations are not made that inadvertently disable these functions.

Developing a thoughtful installation plan, along with reasonable maintenance, will result in an industrial process that is hardened against a long list of potential malfunctions. Discuss your application concerns with instrumentation specialists. Their exposure to many different installations and applications, combined with your knowledge of the process and local conditions, will produce a positive outcome.