Tuesday, February 20, 2018

Wireless Technology in Industrial Automation

Yokogawa wireless transmitter
Yokogawa wireless

Reprinted with permission from Yokogawa.

The use of wireless technology in industrial automation systems offers a number of potential benefits, from the obvious cost reduction brought about by the elimination of wiring to the availability of better plant information, improved productivity and better asset management.

However, its practical implementation faces a number of challenges: not least the present lack of a universally agreed standard. This article looks at some of these challenges and presents the approach being taken by Yokogawa.

Introduction: The Wireless Landscape
In order to understand the ways in which wireless technology can aid the implementation of industrial automation systems, it is first important to clarify what is meant by the word ‘wireless’ in this context. Essentially, wireless can act at several levels within a plant:

  • RFID: At the simplest level, radio-frequency identification can aid asset inspection and tracking, safety and security, and location.
  • Wireless sensor networks: This is possibly the area where most attention is currently being focused, and embraces areas such as condition monitoring, wireless instruments and measurements.
  • Wireless LANs, covering areas such as mobile operator terminals, data logging, security, maintenance and IT. Wireless WANs, including long-distance broadband backhaul and high-bandwidth video applications.
When implemented within a typical plant, as depicted in the typical configuration shown in Fig.1, each of these areas can bring benefits as well as new opportunities. For example, the fact that plant and process information is available anywhere via wireless sensor networks leads to more and better quality information, with the benefits of distributed control and plant asset management spread throughout the plant.

wireless process control
Fig. 1 (click for larger view).
Another important benefit is improved workforce productivity. The fact that there are no wires leads to reduced installation and commissioning effort, while the fact that workers – whether operators or maintenance engineers – can be truly mobile eliminates the need for fixed local panels. Improved plant management results from the improved availability of video surveillance and people tracking for better safety and security, along with a reduced need to access hazardous or remote plant areas.

Wireless Sensor Networks
Of all the elements outlined above, wireless sensor networks are currently attracting the most attention, as most of the benefits directly relate to this area. Apart from the benefits of eliminating signal and power wiring, wireless sensor networks will open up measurement applications in sites that are hard to access, or where the wiring cost cannot be justified. They will also prove invaluable for the modernization of existing facilities, for temporary installations, or for locations where a power source is not available.

Wireless sensor networks also offer enhanced plant asset management through the freeing up of cable resources for higher-priority measurements in existing installations, the replacement of many traditional pressure gauges and temperature indicators, and the ability to make measurements that could not previously be justified. There is also a reduction in ‘blind spots’ through the ability to make measurements on rotating or moving equipment and in remote locations. A further important point is that, once established, wireless sensor networks are scalable: additional sensors can be added at low cost, and temporary measurements can be easily incorporated for process diagnostics and optimization.

Wireless Standards
In developing a universal standard for industrial automation wireless networks, a number of challenges emerge, not least because most license-free wireless networks use the same 2.4 GHz bandwidth, and many sensor networks are based on the IEEE 802.15.4 standard. Clearly there are concerns about coexistence and interference leading to reliability and latency problems and about multiple protocols sharing the same bandwidth.

Users have concerns about security, with the potential for jamming, sabotage and the compromising of network privacy. They also want systems that are open and backwards-compatible, interoperable and cost-effective to implement.

One thing is certain: the industry must strive to establish one global standard which covers communication from sensor to boardroom, which is designed with security in mind, and which is end-user driven. Unfortunately, this ideal scenario is unlikely to occur in the foreseeable future since two standards are currently being used by different industry players: WirelessHART and ISA100.11a. Although the two have some features in common, in reality they are very different. In particular, the scope of ISA100.11a is much wider, since – whereas WirelessHART focuses on monitoring from HART-enabled field instruments, ISA100.11a offers the scope to cover everything from field instruments to control- room integration. Moreover, it is compatible with a variety of protocols including FOUNDATION Fieldbus, Profibus, Modbus and others as well as HART, and allows over 1000 devices in a network compared to only around 250 with WirelessHART.

Yokogawa is committed to supporting ISA100.11a as part of the ISA100 family of standards as a preferred single international standard. In addition the ISA99 Security for Industrial Automation and Control Systems standard will be implemented to warrant overall security and privacy.

Wireless Strategy
Yokogawa is currently in the process of developing and evaluating a number of products for wireless sensor networks, with the emphasis on self-healing mesh network configurations, long battery life for field operation and a high degree of security. Field trials have been carried out to establish the characteristics of 2.4 GHz wireless transmission within typical environments such as refineries or chemical plants, from which a number of important lessons have been learned:
  • 2.4 GHz radio is sensitive to the presence of obstacles (pipework and other metal structures, for example). Wireless is not much affected by the local climate or by the presence of other wireless networks.
  • A mesh network configuration (involving more than two paths) is important for network reliability.
  • Response time is a useful indicator of the radio transmission conditions.
As a result of this experience, Yokogawa is pressing ahead with the development of wireless-based field instruments and access points as the initial stage of a ‘total solutions’ approach, and is implementing partnerships with other organizations to facilitate aspects such as the integration of auxiliary sensors as well as mobile worker networks, integration of surveillance camera systems and long-haul inter-plant connections.
wireless process control
Click for larger view.
A lesson learned from conducted wireless sensor field trials and real project implementations of mobile worker networks is that obstacles may affect the reliability, and hence the quality of service (QoS), of the network. Specifically, the proper location of access points and other devices and the possible need for inclusion of repeaters should be assessed beforehand. This is particularly critical for the successful operation of the mobile worker network, where roaming is essential.

It is expected that wireless sensor networks will gradually be adopted by the process industry. Although ISA100.11a is designed to accommodate control applications, initially the majority of applications will be for monitoring due to battery life limitations. In existing installations the benefits are obvious. Measurements for process monitoring and condition monitoring can be added where the existing infrastructure cannot accommodate them. State of the art greenfield sites are expected to be equipped with intelligent instruments that are mostly connected through wired instrumentation systems such as Foundation fieldbus while having several wireless networks for process and condition monitoring present.

Contact Power Specialties for Yokogawa wireless field devices and systems by calling (816) 353-6550 or by visiting https://powerspecialties.com.

Tuesday, February 13, 2018

RTD Sensors and Accessories for Clean-In-Place Applications

Pyromation CIP RTD
Pyromation CIP RTD
This one page publication features our CIP RTD Sensors and Accessories. Included are General Purpose CIP Sensors, Tank Sensors, Thermowells, and Transmitters.

Clean-In-Place units are provided with a Number 7 polished finish which exceeds 20 uin Ra. They meet or exceed finish requirements set forth by the 3A Sanitary Council Standard.

Download a PDF version of Clean-In-Place RTDS here, or read the embedded document below.

(816) 353-6550

Wednesday, January 31, 2018

Using Orifice Plates to Measure Flow

The orifice plate is the simplest of the flowpath restrictions used in flow detection, as well as the most economical. Orifice plates are flat plates 1/16 to 1/4 inch thick. They are normally mounted between a pair of flanges and are installed in a straight run of smooth pipe to avoid disturbance of flow patterns from fittings and valves.

Three kinds of orifice plates are used: concentric, eccentric, and segmental (as shown in Figure 1).

orifice plate
Fig. 1 - Orifice plates (click for larger view)
The concentric orifice plate is the most common of the three types. As shown, the orifice is equidistant (concentric) to the inside diameter of the pipe. Flow through a sharp-edged orifice plate is characterized by a change in velocity. As the fluid passes through the orifice, the fluid converges, and the velocity of the fluid increases to a maximum value. At this point, the pressure is at a minimum value. As the fluid diverges to fill the entire pipe area, the velocity decreases back to the original value. The pressure increases to about 60% to 80% of the original input value. The pressure loss is irrecoverable; therefore, the output pressure will always be less than the input pressure. The pressures on both sides of the orifice are measured, resulting in a differential pressure which is proportional to the flow rate.
Orifice plate flow pattern
Orifice plate flow pattern (click for larger view)

Differential Pressure Transmitter
Differential pressure
transmitter used to
calculate flow.
Segmental and eccentric orifice plates are functionally identical to the concentric orifice. The circular section of the segmental orifice is concentric with the pipe. The segmental portion of the orifice eliminates damming of foreign materials on the upstream side of the orifice when mounted in a horizontal pipe. Depending on the type of fluid, the segmental section is placed on either the top or bottom of the horizontal pipe to increase the accuracy of the measurement.

Eccentric orifice plates shift the edge of the orifice to the inside of the pipe wall. This design also prevents upstream damming and is used in the same way as the segmental orifice plate.

Orifice plates have two distinct disadvantages; they cause a high permanent pressure drop (outlet pressure will be 60% to 80% of inlet pressure), and they are subject to erosion, which will eventually cause inaccuracies in the measured differential pressure.

Contact Power Specialties with any process flow question or requirement. You can find them by visiting https://powerspecialties.com or by calling (816) 353-6550.

Tuesday, January 30, 2018

Chino IRMA Analyzer Re-Zeroing Calibration Procedure

The Chino IM series is an on-line multi IR wavelength analyzer utilizing the infrared absorption technology for measuring product constituent and/or thickness. Watch the video below for instructions on re-zeroing the IRMA calibration.

(816) 353-6550

Thursday, January 25, 2018

Easily Select a Fox Thermal Gas Mass Flow Meter with Help from this Tool

Saving time and being accurate. Two very important elements to every engineer's workday. Anytime a tool comes along to provide both, it needs to be featured.

Fox Thermal, the manufacturer of thermal gas mass flowmeters, has an excellent Web-based configurator that's easy to use and provides accurate, detailed output.

After a quick registration process, anyone interested in applying a thermal gas mass flowmeter will be guided through a meter section process. The app will help you select the correct model, and then begin asking more specific application questions.

Finally, the application presents a summary of your requirements, and then checks if you want to have the Fox Thermal sales department provide a quotation.

Check out this video for a tutorial on how the gas mass flow meter configurator works.

Courtesy of Power Specialties
(816) 353-6550

Tuesday, January 16, 2018

Yokogawa Model GX10/GX20/GP10/GP20 Paperless Recorder First Step Guide

Yokogawa Model GX10/GX20/GP10/GP20 Paperless Recorder
Yokogawa Model GX10/GX20/GP10/GP20 Paperless Recorders
The Yokogawa GP series is an industry-first multi-point touch panel, to improve intuitive and smart operator control. Users can scroll, pan, zoom historical data, and even write freehand messages on its dust-proof and water-proof display. It delivers industry leading reliability and measurement accuracy. The GP series is ideally suited for monitoring or troubleshooting long term physical or electrical trends.

The GX series is an industry-first multi-point touch panel, to improve intuitive and smart operator control. Users can scroll, pan, zoom historical data, and even write freehand messages on its dust-proof and water-proof display. The Yokogawa GX series delivers industry leading reliability and measurement accuracy. Its custom graphics accommodates application or process-specific displays, while a wide range of communication protocols guarantee compatibility with your network architecture. It's simple for operators to view and retrieve past data with automatic email and FTP notifications.

Below in the embedded document is the First Step Guide for your review.

Saturday, December 30, 2017

Happy New Year from Power Specialties

With 2017 coming to a close, all of us at Power Specialties wanted to reach out and send our best wishes to our customers, our vendors, and our friends! We hope that 2018 holds success and good fortune for all of you.