How Far Is Too Far with Wireless Process Signals?

Wireless communication technology, adapted for industrial use, has brought a host of benefits to companies bold enough to include it in their process control infrastructure. The use of wireless communications to deliver operating data from sensor to control station is no longer avant garde. The innovators, those first to deploy new technology, have long ago pushed the industrial process control world sufficiently up the learning curve to a point where applying wireless is a fairly straight forward matter.

Are there limits, practical or theoretical, to the length of a wireless connection?

Consider the bandwidth options for wireless transmission of a process signal. The 2.4GHz and 900MHz frequency bands each have their advantages for shorter distances in the range of a few feet to several miles. The ability to connect over any distance is impacted by a number of factors, not the least of which are allowable transmission power level and obstacles to the clear line of sight. One way to extend the range of a device is to install a repeater at some point along the transmission path. Repeaters will receive a fading process signal and transmit the signal at the full available strength, increasing the distance over which the information can be transmitted. Repeaters can also be useful for bypassing obstacles in the transmission path.

What if connection is needed over a longer distance?

There are other options for bandwidth that can extend beyond a few miles. If service is available at transmission and receiving sites, cellular networks may be a workable option. Satellite data transmission is also a viable option that can provide global connectivity.

Distance is not really a great hurdle to overcome when it comes to establishing an industrial wireless connection. Share your industrial wireless challenges with application experts. Combining your process knowledge with their wireless expertise will produce effective solutions.

Piping & Instrumentation Diagrams in Process Control

All processes benefit from P&ID

P&ID's (Piping & Instrumentation Diagrams), or Process and Control Flow Diagrams, are schematic representations of a process control system, used to illustrate the piping system, process flow, installed equipment, instrumentation, and functional relationships among all the system components.

Intended to provide a comprehensive picture of all piping and associated hardware, including physical branches, valves, equipment, instrumentation and interlocks, the P&ID employs a set of standard symbols representing each component of the system such as instruments, piping, motors, pumps, etc. The use of standard symbols provides a universal depiction that can be read and understood by operators, technicians, outside contractors, and other similarly trained individuals.

P&ID’s can be very detailed and are generally the primary source from where instrument and equipment lists are generated, also being a very handy reference for maintenance and upgrades. P&ID’s also play an important early role in safety planning by enabling an understanding of the operating states and relationships of all components in the system.

Know Analynk Wireless - Introductory Video

Analynk Wireless is an innovative designer and supplier of wireless instrumentation for the process control industry. Instruments and equipment have been successfully implemented in numerous applications including temperature measurements, 4-20 mA bridges, discrete inputs/outputs, pulse inputs, lighting and pump controls. The company's products are used in both hazardous and non-hazardous locations. Analynk Wireless also manufactures a line of traditional wired process measurement and control instrumentation under the brand name Telmar Instruments.

Share your wireless connectivity challenges with the experts at Analynk. Combining your process knowledge with their expertise with produce effective solutions.

Comparison of 2.4 GHz and 900 MHz for Industrial Process Control Wireless Connection

Wireless transmission of measurement and control signals are the future, and present, of process control. WiFi is already prevalent in higher density environments and providing benefits of reduced cabling and more. Wireless communications also can be used to connect devices over substantial distances, even globally. This article will focus on applications of moderate to long distance that will employ point to point communications of dedicated devices. Here is an illustrated example, with level measurement instruments on storage tanks located remotely from a data monitoring station.

Example of wireless connection between remote tanks and data collection and control center

In establishing a wireless process signal connection between the two points in the example, an initial consideration will be whether to employ 900 MHz or 2.4 GHz as the radio band. There are some general implications associated with the selection.

• Signal attenuation over any distance is greater for 2.4 GHz than 900 MHz. This generally means that 900 MHz can cover a greater distance and provide a signal of sufficient strength to properly communicate.
• Atmospheric attenuation for either frequency band is about the same, with a very slight advantage to 900 MHz.
• Both frequencies require "line-of-sight" to provide predictable and reliable operation. Obstructions within that zone can degrade the signal. Any obstructions with dimensions approximating the wavelength of the signal tend to have a greater impact. The wavelength of a 2.4 GHz signal is 12.5 cm (4.52 inches), 900 MHz is 33.3 cm (84.6 inches). 2.4 GHz signals are susceptible to interference by smaller objects in the transmission path than are 900 MHz signals.
• Without getting too technical, the height of a 900 MHz antenna will need to elevated to a greater distance the that of a 2.4 GHz antenna in order to provide what is known as "free space propagation". This is related to the Fresnel Zone and has greater impact as transmission distance increases.
• FCC rules allow larger transmit power ratings for 2.4 GHz radio signals than 900 MHz, increasing the potential range for 2.4 GHz.

Evaluate your potential installations with the above points in mind. Their impact on any particular application can vary depending upon the distance, topography, and potential obstructions. Share your wireless communications challenges with the experts at Analynk Wireless. Combining your site and process knowledge with their product application expertise will produce an effective solution.

Analynk Extends Offering of Hazardous Area Access Point Enclosures

AP411 for the Meraki MR72 Wireless Access Point
is Analynk's latest addition to the product line

Analynk Wireless manufactures equipment for transmitting process control signals via WiFi, radio, satellite, and cellular networks. One of their continuously expanding product lines is the Hazalynk series of explosion proof access point enclosures for installing wireless access points in hazardous areas.

The company currently has specific models designed for simple accommodation of wireless access points from Symbol, Cisco, Meru, Meraki, Aruba, HP, and Motorola. Each model is specifically configured to house a particular model wireless access point. Antenna openings, cables, and internal mounting bracket are all coordinated to provide easy installation of the wireless access point. Explosion proof antennas suitable for the access point are included with each enclosure.

The latest addition to the product line is intended for use with the Meraki MR72 Access Point. A data sheet for the unit is included below, or you can contact Analynk for more information about this or any of their other industrial wireless products.

New Wireless Network Access Point Enclosure for Hazardous Area from Analynk Wireless, LLC

Wireless Access Point Installation in Hazardous Area

Wireless access point enclosure for hazardous area

Here is your challenge. Your facility is expanding its wireless network coverage into another processing area. That new processing area also happens to be classed as hazardous. How are you going to place a wireless access point in that area to provide good wireless coverage?

Analynk Wireless manufactures industrial wireless communications products suitable for use in hazardous areas. One product line, Hazalynk, includes rated enclosures for popular wireless access points to enable installation in hazardous locations. Preconfigured models accommodate units from Cisco, Symbol, Meru, Aruba, Hewlett Packard, Motorola, and other brands. If there is not a preconfigured model for your preferred access point, contact Analynk. Arrangements are possible to accommodate most brands and models.

The Hazardous Area Access Point Enclosures are designed specifically to house the customer's selected access point device. The matching enclosure for an access point will have:

• Custom mounting bracket mating to the customer's access point.
• UL listed enclosure for subject hazardous area, including antenna locations coordinated with access point device arrangement.
• UL listed explosion proof antenna, one or more as need for the subject access point.
• All hardware, mounting plate, and RF cables to simplify installation and startup

A product specialist can help you with the latest available information. Contact Analynk to discuss your application and how to best fulfill your hazardous area wireless communication requirement.

Wireless Communications for Industrial Automation Continues to Expand Because It Performs

Wireless communications capabilities for process control
extend beyond WiFi

Wireless connection between a sensor and control or monitoring station is not new anymore. Products have matured, familiarity with the technology is widespread. Certainly, there are still large swaths of industrial installations that do not utilize the technology. This can be for any number or reasons, but new industrial technology tends to follow a predictable course throughout its adoption. There will be innovators and early adopters that can justify higher risks with the prospect of great returns. Many industries and companies will wait until perceived technological difficulties with implementation are overcome and products become more mainstream and easy to apply. That is where industrial wireless is today. Assembling complete working systems is a straight forward operation. Costs are comparatively modest. It's easier to visualize a payback.

Let's review some of the benefits a wireless installation can bring.

• 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.

Analynk Wireless manufactures a broad range of wireless communications equipment for industrial process control and automation. Share your wireless connection challenges and ideas with the experts at Analynk and start benefiting from the technology. It's not new anymore. It's mainstream.