Test Run That Wireless Connection

symbol for wireless process communications or industrial wireless
The application of wireless connectivity among process measurement and control devices continues to expand throughout all industrial spheres. While wireless transmission of process measurement and control signals has not been new technology for quite some time, there are still many opportunities for its application.

Wireless communication for industrial applications is well beyond the point of early technology adoption. Protocols are in place, products for the transmitting and receiving of wireless process signals are mature. As a designer, engineer, manager, or operator of a process, you should confidently consider wireless connections between measurement and control or recording devices as part of any new installation or upgrading of existing facilities.

As part of the implementation of a wireless connection, the questions concerning range and signal attenuation usually come up. Basically, will the signal remain sufficiently strong across the distance necessary to make the connection?

Analynk's wireless demo kit includes a model A750 receiver and A753 transmitter both housed in NEMA 4 enclosures. The kit operates at 900 MHz with full 1W power. Locate the transmitter and receiver at points where you wish to establish a wireless connection. You can provide your own input signal, or use the provided simulator to show that a wireless connection can be established and function in a manner that will give you confidence to move forward with implementation. The kit is useful for testing out possible new locations for distance and signal strength. You will use it as wireless communications expand through your facility. Test the location first, then order the needed wireless equipment. It's a solid low risk solution.

Analynk is a manufacturer of both wireless and wired devices for process measurement and control. The company's offering includes a wide array of standard products, as well as integration and customization to meet specific project requirements. Contact the specialists at Analynk to discuss your industrial wireless application requirements.


Options for Industrial Wireless Transmitter and Receiver Enclosures

drawing of optional enclosure for industrial wireless transmitter or receiver with antenna
Analynk Wireless provides a wide selection of optional
enclosures and prewired transmitters and receivers.
Analynk Wireless, with their extensive array of available options, can save customers time and effort when implementing wireless connections among process measurement and control devices.

The enclosure for the transmitting and receiving gear should be properly sized to house the necessary devices, while providing adequate service space and an external antenna connection. Analynk has already made suitable enclosure selections, delivering good design practice, even prewiring, so the system is ready to install and power up right out of the box.

The enclosure options are a few of the many preconfigurations that Analynk can accomplish for customers. Making wireless connections among process measurement and control instruments and equipment a smooth and cost effective option is the company's mission. Share your connectivity challenges with the experts at Analynk, combining your process knowledge and experience with their wireless connectivity expertise to develop an effective solution.

Compact Tachometer

DIN rail mount tachometer with analog output
The Analynk 618 Series Tachometer has a compact DIN rail
mount package
Analynk Wireless is best known for the wide array of radio transmitters and receivers enabling wireless connectivity of process measurement and control instruments and equipment. The company also manufactures a many specialty analog wired devices that can easily solve process measurement and control challenges.

The 618 Series of tachometers use a frequency input from a pickup to produce an analog signal output usable by many industrial controllers. The tachometer mounts easily in a control enclosure on a 35 mm DIN rail and can accommodate a wide range of input pulse voltages. The unit can be configured to provide one or two alarm contacts, along with one of several common analog output signals.

More information is provided in the datasheet included below. Share your process measurement and control challenges with the application engineers at Analynk, leveraging your own process knowledge and experience with their product application expertise to develop effective solutions.



Custom RF Cables Can Speed Your Wireless Installation

Custom RF cables with various connector types
Custom RF cables speed installation of industrial
wireless gear.
Upgrading or installing new process instrumentation often requires some level of specialty work that can extend beyond the normal scope of activities performed by in-house technicians. With some planning and smart outsourcing, many gaps in your own capabilities can be filled and expeditious progress made toward the end goal.

Industrial wireless gear will utilize a special cable to connect a remotely located antenna to a receiver or transmitter. Analynk Wireless, as a complement to their line of wireless transmitters, receivers, antennas, and related equipment, custom fabricates RF cables to help provide a complete installation package for their customers and enable the use of fewer source vendors. Any application can be accommodated, and design and planning assistance is available.

Share your wireless connectivity challenges with the experts at Analynk. Leverage your own process knowledge and experience with their product application expertise to develop an effective solution.

Industrial Wireless - Multiple Transmitters With Master and Slave Receiver

industrial wireless multiple transmitter array with master and slave receiver
Multiple transmitters can connect with a single receiver which
retransmits the signal to slave receiver.
Industrial wireless connections are becoming more prevalent, due to their low cost, effectiveness, and ease of installation. Being knowledgeable of the various ways in which connections can be established and signals routed can increase your proficiency at putting in place useful connections among process measurement and control points.

One easily implemented scenario enables multiple transmitters to deliver process measurements from separate locations to a single master receiver. The receiver can re-establish the analog process signals at its outputs, for use by monitoring and control equipment. Additionally, it those process measurements have use in another additional location, the master receiver can forward the signals to a slave receiver. This allows the individual process measurements to be utilized over a potentially wide area or distance not easily or economically spanned with cabling.

Analynk Wireless has a library of standard product modifications that have been previously utilized to meet special connectivity challenges. Share yours with them and build a solution.

Process Control Methods: On/Off Control

industrial control or alarm module
Telmar Alarm/Limit Controller
Many athletes are familiar with the term “turning it on” or “turning it up,” typically in reference to a great performance or improvement in play. “They really turned it on in the second half” or “They turned it on in the third quarter.” The frustrating part for those athletes, though, is that they sometimes cannot control when the magic happens. Sure, they can train well to put themselves in positions to have great games, but very few athletes have the ability to flip a switch and ‘turn it on’ by command; those who possess anything close to controllable magic may go down as some of the best to ever play their respective sport.

Thankfully, in the world of process control, a system exists where it is possible for a control element to be determined by either being turned on or off: on/off control theory is based on the idea that there are two positions for a specific control element, i.e. open or closed. The lack of a middle-ground position may sound absolutist at first, and it’s not the most complex method employed by process controllers, but there are distinct advantages to the on/off system. For example, on/off control is often used industrially; however, basic home appliances such as fridges and ovens both utilize on/off control. The oven and the fridge are both used for straightforward purposes, matching the control method – such is why on/off control is not very popular for use in a commercial setting requiring a wide range of complexity. Another prime example of on/off control is a heating system, where, when the house gets cold, the heater turns on, and when the house reaches a certain temperature, the heater turns off. The process variable, in this case the temperature, is determined by the output, meaning that when the output crosses a certain threshold, the change occurs in the system being switched from either on to off, or off to on.

Due to the aforementioned nature of the controlled output being either 100% or 0%, this method of control is not the best for every application. One of the most common uses for on/off control relates to HVAC systems, where maximum output is being delivered or the system is off. To prevent nearly constant oscillation between the desired temperature and the range either above or below, a staple of on/off control oriented processes is the deadband. A deadband is essentially the process control equivalent to a demilitarized zone, a designed neutral space where no change in the output signal occurs. Let’s say the heating thermostat in a house has a setpoint of 65°F. If the deadband range of the thermostat is 4°F, the furnace will start when the measured air temperature is 61°F (65 minus 4). The furnace will run until the air temperature reaches 65°F. The deadband, depending on the capability of the controller, can sometimes be repositioned in relation to the setpoint, but the key function of deadband remains the same. No change in controller output state occurs while the process variable, in this case room temperature, is in the deadband. This keeps machinery from rapidly cycling on and off, with resulting excess wear and tear or other negative consequences. The deadband compensates for the disadvantage of such an on/off control system in terms of absolution. Another process which illustrates on/off control is a liquid tank filling operation. When liquid in a tank reaches a certain level, level sensors and switches exist which, upon sensing the liquid  at a predetermined level, will send a signal to a controller, causing a fill valve to close or pump to cease operation.

The same elements which make on/off control appealing and compatible with some processes also render some disadvantages when applied in other scenarios. The aforementioned rapid cycling may have been somewhat corrected thanks to the theory and implementation of the deadband, but issues relating to the black-and-white operational principle also provide a potential drawback in different systems. A delay with a time value greater than zero exists in a good amount of practical on/off control situations where ‘dead time’ impacts the time it takes for an on/off position to switch. This means the value thresholds established for each position may be crossed before the opposing position kicks in to bring the value back to within the intended control range. For processes requiring strict value limits to be maintained with little or no margin for error, this particular truth of on/off control is extremely hard to ignore. Also, systems which are working together to form a more complex, connected process are rarely used in conjunction with on/off control because when the oscillations in on/off controlled systems occur – especially in processes where deadbands are inapplicable – they could ricochet through the connected system and introduce unforeseen complications and process instability. The ‘overshooting’ of the element being controlled is a common risk to consider when evaluating the potential disadvantages of on/off systems, causing them to be typically incompatible with environments where precise regulation is required. That said, the relatively low cost and simplicity of this process control method makes on/off control a rugged and long-lasting choice for systems which can function well within the limitations of the controller.

Properly applied, on/off control methodology can provide an inexpensive and effective solution that is easy to apply and maintain. Analynk, under their Telmar brand name, manufactures numerous analog devices that can be applied in a process control application. Share your process control challenges with product application specialists, leveraging your own experience and knowledge with their product application expertise to develop effective solutions.

Overcoming Signal Attenuation in Industrial Wireless Transmission

antenna symbolizing radio transmission
Wireless signals facilitate mobile and remote connections
of industrial process measurement and control equipment
Wireless connections for process measurement and control devices continue to grow in their application range and adoption. The ease with which remote, mobile, even nearby devices and equipment can be connected to monitoring and control stations keeps wireless connectivity a considered option for many facility modifications and additions.

How do you know if the wireless connection you intend to establish will work? It's not a question of whether the gear will function properly, but one of whether the signal will be able to find its way from point A to point B. Signal attenuation is the reduction in signal strength that occurs along the path between two points. Too much attenuation and the signal is not effective in delivering data to the destination. Two main elements contribute to signal attenuation.

Distance

Radio signals deteriorate over the distance traveled. This attenuating factor can be overcome by boosting transmission power, but regulatory limits are in place that disallow much in the way of increasing transmission power. Keeping in mind that signal attenuation at a level that renders a transmission indecipherable, just caused by distance alone, requires a very substantial distance. That said, there are several effective solutions that can be put in place. One involves increasing the height of the transmission antenna. Another is to install a repeater at a point along the transmission path. A repeater, properly placed, will effectively receive the signal from the transmitter, then transmit a new signal of greater strength that replicates the original received data. The use of repeaters can greatly extend the distance spanned by a wireless transmission.

Obstructions

Many are familiar with the objective of establishing "line of sight" transmission paths between transmitter and receiver. Physical structures and materials of all types should be considered detrimental to the transmission of wireless signals. A basic understanding of Fresnel zones is helpful in overcoming the barriers presented by physical obstructions. As with distance, antenna height or location can be a significant factor in dealing with the challenge of obstructions. Repeaters, described earlier, can be instrumental in getting your signal over or around otherwise impassable obstructions.

Routing wireless signals presents different, but no more complicated, challenges than routing cable. The tools are different, the medium is different, but you are still just trying to find a way from point A to point B. With experience, wireless signal propagation becomes is mundane is routing conduit.

Share your industrial wireless ideas and challenges with the experts at Analynk Wireless. Analynk Wireless manufactures equipment used to establish wireless process connections across the room, across the plant site, across the highway, and around the globe.