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.

Industrial Control System Cybersecurity Primer - White Paper

Industrial control systems present unique
cybersecurity challenges

The International Society of Automation is offering a free white paper entitled “What Executives Need to Know About Industrial Control Systems Cybersecurity”. The article provides useful commentary and information that establishes the scope of cybersecurity in the industrial process control space and provides a basic framework for understanding how every process may be impacted by lax cybersecurity efforts. The author, Joseph Weiss, differentiates Industrial Control System (ICS) cybersecurity from that of organizational IT through a review of various attributes common to both types, including message confidentiality, integrity, time criticality, and more. Any reader’s awareness and understanding of the cybersecurity risks to their operation will be enhanced through this article. I finished reading the article wanting more on the subject, and ISA is certainly a resource for additional content.

A quote from the article...

“Cyber incidents have been defined by the US National Institute of Standards and Technology (NIST) as occurrences that jeopardize the confidentiality, integrity, or availability (CIA) of an information system.”

ICS cybersecurity extends beyond preventing malicious outside intruders from gaining access. It is an important part of maintaining the overall operating integrity of industrial processes. A holistic approach is advocated to identify physical risk factors to the process and its componentry (post on device protection), as well as vulnerabilities that may prevent exploitation by unauthorized parties. Weiss goes on to describe the role and qualifications of the ICS Cybersecurity Expert, essentially an individual that can function effectively as an IT cybersecurity tech with the added skills of an industrial control systems expert.

A synopsis of attack events is provided in the article, with the author’s conclusion that not enough is being done to secure industrial control systems and the risk exposure is substantial in terms of potential threats to personnel, environment, and economy. By providing your name and email address, you can obtain the white paper from the ISA website. Your time spent obtaining and reading the article will be well spent.

For any specific information or recommendations regarding our products and cybersecurity, do not hesitate to contact us directly. We welcome any opportunity to help our customers meet their process control challenges.

Two-Wire vs. Four-Wire Transmitter For Analog Process Measurement and Control Signals - What Really Matters?

One of many form factors of two wire transmitters
for industrial process measurement and control
Courtesy Telmar Instruments

Transmitters are everywhere in process control. They take a sensor output signal,amplify and condition it, then send it to monitoring and decision making devices. The most common analog electrical signal used for transmitting process control signals is a 4-20 mA (milliampere) current flow. It has succeeded in its adoption for a number of reasons, not the least of which are its resistance to interference and ability to transmit a signal across a substantial length of cable.

Aside from the sensor connection, there are two basic wiring schemes for these devices. The simplest employs just two conductors to transmit the signal and coincidentally provide operating power for the transmitter electronics. This type of transmitter is commonly referred to as a "loop powered" or "two-wire" device. A DC power supply, typically 24 volts, is wired in series with the 4-20 mA output signal and the transmitter derives its operating power from this source. Loop powered devices generally consume very little power, but process designers must consider the total resistance imposed on the loop by all connected devices. The cable, unless the length is monstrous, poses a measurable but comparatively small resistance. Careful consideration should be given to the resistance imposed by receiving devices, especially if there are several in series, receiving the loop signal. The output voltage of the power supply and the maximum tolerable voltage of the connected devices will serve as limiting factors on loop instrument quantity. Where they can be applied, two-wire transmitters offer a straight forward solution for delivery of analog process measurement signals.

A "four-wire" transmitter gets its name from, you guessed it, the two pairs of wires used to provide operating power and a signal transmission path. Provided with a separate power source, possibly even 120 volts AC, this transmitter type will often be found in applications where the sensor may have power requirements that cannot be met with the limitations inherent in the loop powered device. While it may seem that the separate power supply negates the need to consider total resistance load on the signal loop, this is not the case. The signal loop still will be limited by the DC power supply that serves as the driving force of the loop.

In many cases, the question of "two-wire or four-wire" will be answered by the transmitter manufacturer. Since the two-wire scheme is a less burdensome installation, it may be the only product offering when a suitable device can be designed for an application. That said, a diligent search will probably find two and four-wire versions of transmitters for almost every application.

What are some decision making guidelines?

• Some types of transmitters have sufficiently high power requirements that they cannot be loop powered. In this case, four-wire may be the only option.
• For low resistance loads, use 2 wire transmitters for a simpler installation.
• Allow some headroom in the loop resistance to accommodate at least one added receiving device in the future. For example, a temperature signal may serve as an input to a controller now, but need to service a recording device potentially added in the future.
• Distance should not be mindlessly overlooked, but is generally not a limiting factor, as most installations would be compatible with the distance limitations for two- or four-wire device output signals. 
• When signal transmission distances become unwieldy, due to cabling costs or other factors, consider a wireless transmitter instead of a wired device.

The important aspect of applying 4-20 mA signal loops is to maintain the capability to add another receiving device to the circuit. The use of information in the form of process signals has been growing for a long time and is likely to continue. It is certainly easier to wire an additional device into an existing loop, than to install an additional sensor, transmitter, power supply, and cabling to accommodate the additional device. 

Analynk provides wired and wireless solutions for delivering analog process control signals. The wired devices carry the company's Telmar brand name. Wireless solution products carry the Analynk and Sensalynk brand name.

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Creating Wireless Process Connections Is ABC Simple

Industrial wireless is not new, it is a mature technology. With the products available today, implementing a wireless process signal connection is no more difficult than installing a simple process controller. Analynk is a part of that simplicity, manufacturing modular receivers, transmitters, and companion products enabling operators at any scale to effectively deploy a 900 MHz or 2.4 GHz wireless solution.

There are many instances where a wireless solution provides distinct advantages over wired installations. Understanding the simplicity of wireless installations, and that product based solutions are readily available, can unleash your ingenuity at solving process control challenges using wireless communications. A previous article may help you recognize opportunities to avoid expensive or difficult cabling, or actually make connections you thought were impossible.

Let's look at a basic installation that measures temperature at a remote location (the measuring station) and transmits the signal to your office (the monitoring station).

Here is all you need:

• Power supply to operate the temperature measurement instrument and the Analynk transmitter. Analynk transmitters consume little power and can be provided with photovoltaic power supplies, if needed.
• Temperature measuring device of your choice with 4-20 ma output signal and up to two discrete outputs. It does not need to be wireless. 
• Analynk transmitter located at the temperature measurement station to convert the 4-20 ma temperature signal to digital format and send it to the monitoring station. The connection between the temperature measuring device and the Analynk transmitter is wired.
• Analynk receiver located at the monitoring station to receive and decode the signal from the Analynk transmitter, converting it back to 4-20 ma. A wired connection between the receiver and your monitoring or recording equipment delivers the 4-20 ma temperature signal to its destination.

The simple wiring connections to the transmitter and receiver differ little from those of most other devices (see the ABC’s on the illustration).

A - Connect a power source to operate the unit
B - Connect the input signal (if it's a transmitter) or output signal (if it's a receiver).
C - Connect discrete inputs (if it's a transmitter) or outputs (if it's a receiver).

Wiring diagram for Analynk Model A753 wireless transmitter

Setting up the transmitter and receiver takes no more technical knowledge than other modern control devices. You follow instructions to set a few parameters, calibrate, and put the system into operation.

You can gang inputs and outputs together with an expander module and use a single transmitter and receiver to deliver multiple sensor signals. All units are DIN rail mounted with removable terminals for simple, organized installation and replacement.

Wireless connections can expand your operating capabilities, as well as business opportunities. Analynk has made the implementation easy. Use your creativity and ingenuity to bring new applications to your operation. Contact Analynk anytime to discuss your ideas or get the help you need to put your ideas into action.

Process Control - Extending Wireless Process Signals

Analynk's wireless repeater extends your process signal
transmission distance or routes it around obstacles.

The simplicity of bringing a wireless connection to your process control application extends to overcoming one of the challenges that can arise due to extended distance or substantial obstacles between the transmitter and receiver. Analynk provides a repeater that can be strategically placed between transmitter and receiver to extend the overall transmission distance, or route the signal around obstacles that may otherwise degrade the transmission. The data sheet included below describes how easy it is to apply and provides all the technical details.

Contact Analynk with your process measurement and control wireless communication challenges and get get solid practical solutions.

Analynk Model A759 Wireless Repeater from Analynk Wireless, LLC

Process Monitoring and Control - Where You Can Make Good Use of Wireless

Analynk empowers industrial process operators at any scale to bring the functional benefits of industrial wireless communication to their applications. The company provides easy to implement wireless hardware solutions that can be economically applied to even as single data point.

Talk a look at our short video for some application suggestions. Ramp up your ingenuity and develop ideas for your facility or operation. Contact the experts at Analynk for solutions. We enjoy hearing new and creative ideas for meeting process control challenges with wireless.

Industrial Wireless Communications - Think About Where You Can Use It

Wireless communications applications with beneficial impact
are everywhere, Imaginative thinking is needed.

Analynk builds equipment that empowers anyone with an industrial process control application to make signal connections from sensors to controllers or recorders over distances not practically cabled. The cost and available scale of this technology has reached a level where smaller companies can incorporate it into their operations to increase functionality and efficiency. If you have not done so already, it is time to become familiar with the application basics of this technology and start evaluating your operations for ways to beneficially use industrial wireless communications.

In a simplified fashion, here is how you do it.

• Identify what you want to measure. Typical examples include temperature, pressure, contact closure, or anything else for which a sensing or detecting device is available.
• Find the device most suited for your measurement. It will be convenient to use a device providing a commonly used output signal. Examples include 4-20 ma, 0-5 VDC, and others.
• Select the communications band that best suits your application. Short distances, up to several miles, often use 900 MHz or 2.4 GHz. You can also use the cellular network or one of several satellite networks for extended coverage.
• Select a compatible transmitter, like those from Analynk, to convert the sensor output signal into digital form and transmit it across the network.
• Select a compatible receiver, also available from Analynk, to receive the transmitted signal and convert it back into the original signal form. This output signal will connect to your control or monitoring equipment.
• If you need to send a responding control signal back to the remote location, follow the same plan with the transmission and receiving equipment reversed.

The first time you do it, there will be some things to learn, progress may be a little slow. Once your first attempt is completed, you will understand what needs to be done and further implementation will proceed quickly. There are uncountable applications for this technology that can enable your organization to increase effectiveness, broaden the scope of your operation or service offering, and build a more efficient process. Data points that were previously out of reach are now accessible in real time. Knowing the capabilities of industrial wireless will enable you to recognize useful applications throughout your organization.

You can always contact the specialists at Analynk Wireless to discuss your potential applications. They will help you meet application challenges and get connected.