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How Do Temperature Data Acquisition Systems Work

temperature data acquistion

temperature data acquistion

Data acquisition systems are, at the most basic level, systems designed to collect data on a particular aspect of a physical process. Though long used in both industrial and scientific contexts, a growing number of hobbyists and semi-professional users are now recognizing the advantages of data acquisition.

Temperature data acquisition systems may be regarded as a sub set of generalized data acquisition systems. Temperature is often one of the most critical variables in any system, whether one used for industrial production or in specialized applications such as racing vehicles.

In addition, collecting data on the temperature of a system is often a critical safety requirement. If your equipment runs at its optimum only within a very narrow temperature range, or can be damaged by excessive heat or cold, you need to ensure that the data you are collecting on this variable is accurate and reliable.

There are several things to consider when setting up a data acquisition system for temperature, as there are with any kind of data acquisition system.

For more information on temperature data acquisition please take a look at our Nyquist and other DAQ Products.

Primarily, three factors need to be thought out:

 

Sensors

Perhaps the most critical part of your temperature data acquisition system are the sensors – the devices you will use to measure temperature. Unfortunately, it is very difficult to recommend sensors here, simply because the range of temperatures your equipment works within may be significantly different depending on the type of system you run.

To state the obvious, however, make sure that your sensors are able to deal with the expected (or even unexpected) temperatures produced by your system – a sensor freezing or overheating, and then giving inaccurate readings, is a sure way to damage your equipment.

Data Aggregators

The signal produced by your sensors must then be fed to a device that is able to aggregate and store the temperature data produced. In days past, the most common way in which this was done was by having dedicated Integrated Data Loggers in each piece of machinery. Then came DAQ cards, which represented an advance, but still required dedicated workstations to be set up for each part of the system being monitored.

Nowadays, a good approach is to go for a portable data acquisition system. These are normally stand-alone units, able to run under their own power and to upload data via a wireless network. This is especially useful when the system being studied is inherently mobile, or operates in a hazardous environment.

 

Data Analysis

Once temperature data has been collected, it must be fed to a central location and analysed. Whilst in the past this was typically done through bespoke software, which required technicians to know a number of programming languages, today there are better approaches.

Many of the portable data acquisition systems mentioned above come equipped with dedicated analysis software which requires no specialist knowledge to implement and use. This is especially useful for amateur or semi-professional users, giving them access to powerful temperature analysis tools that were previously the sole domain of highly trained engineers.

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How Field Data Acquisition Works and Where to Buy Them

image of daq basics background

image of daq basics

Field Data Acquisition presents significant challenges for engineers, but in recent years a new generation of DAQ devices have come onto the market that aim to take the hassle out of the process.

These devices are typically able to run under their own power for significant periods and in surprisingly difficult environments. They are lightweight and compact, meaning that they can be incorporated into many systems with little hassle. They are also able to upload data to a central repository via wireless networks, which makes the collection of previously inaccessible data possible.

Our products offer the latest in field data acquisition. To find out more refer to our product page.

 

The Challenges of Field Data Acquisition

There are several challenges to be overcome when trying to collect data in the field. First and foremost, one problem is that whilst the system under study might be a large, rugged, mechanical piece of machinery, data acquisition systems are notoriously fragile.

This can be a problem if the system you are collecting data on produces, or works within, a hazardous environment. In days past, it was often the case that every piece of machinery had its own dedicated data acquisition system, and was hard-wired to a dedicated computer terminal. At best, this meant the expense of running delicate cables far enough away from the machinery to keep the engineer safe. At worst, it meant that data acquisition was only performed during shut downs.

Another challenge of field data acquisition is that in many cases the system under study is inherently mobile, such as a vehicle. Since, as already pointed out, most legacy DAQ systems required hard links, these systems were essentially unable to access data from mobile machinery.

 

The Solutions

Much time and thought has been expended in trying to overcome these challenges, and the new DAQ systems coming onto the market go a long way to overcoming them. Modern DAQ systems are increasingly based on mobile DAQ devices, which are inherently portable in themselves.

Nyquist DAQ in action

These devices achieve this portability in several ways. Primarily, instead of requiring a hard link they are able to collect data from a variety of sensors, aggregate this, and then upload it to a central repository via commonly used wireless networks. Some of these devices even have the ability to produce their own Wi-Fi signal, making connecting to them in the field very straightforward.

They are also admirably light and compact. This means that even in machinery where internal space is at a premium, or in performance contexts where extra weight would be a hindrance, they can be incorporated into the system under study with a minimum of effort or performance loss.

Being able to incorporate a data logger into the design of machinery, and fetching data from it wirelessly, also means that time is saved that would be otherwise spent disassembling systems in order to download the data collected.

Lastly, these portable devices come equipped with an on-board suite of software that means they are able to do quite complex data manipulation by themselves, dispensing with the need for a dedicated workstation whilst in the field.

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How Multi Channel DAQ Works

image of daq basics in action

image of daq basics in action

At their most basic level, data acquisition systems are systems that collect and aggregate data on an external physical system. Whilst much thought is often put into the choice and design of sensors for DAQ systems, less goes into the choice of the data loggers these sensors are connected to.

One of the major advances of the past few decades has been the advent of multi-channel data acquisition systems. These systems are able to accept and aggregate a variety of incoming signals, whether analog or digital, and collect them in a format which is easily accessible for external data analysis software.

The History of Multi-channel Data Acquisition

In order to understand why multi-channel data acquisition was so revolutionary when first introduced, it is worth looking at the way that DAQ systems worked before the advent of multi-channel devices. Typically, a bespoke data acquisition system was required for each piece of machinery being monitored, often with obscure and mutually incompatible hardware for each.

As such, each DAQ, and in some cases each individual sensor, was hard linked to a dedicated PC workstation. This not only meant the extra expense of running delicate and unreliable cables to numerous discrete workstations, but also required arcane, custom software to be running on each terminal also.

types of DAQ systems

And of course, for systems that are inherently mobile, or operate within hazardous environments not conducive to PCs, data acquisition was almost impossible.

Multi-channel data acquisition changed this by allowing one device to collect data from a vast variety of sensors simultaneously. This had great advantages at all stages of the data acquisition system. By feeding the signals from a variety of sensors into one data collection device, DAQ systems were made significantly smaller, and could therefore be fitted to systems where space constraints previously limited this.

Multi-channel data acquisition devices also meant that one work station could easily aggregate all the data being logged from a particular system, greatly simplifying workloads and data analysis.

Choosing a Multi-channel Data Acquisition System

Today, almost all high-end DAQs for general use are multi-channel. Though each system offers its own advantages and disadvantages, one of the major distinguishing features of each is the number of channels available for data.

Some DAQ devices offer minimal channels, down to just two in some cases, and others offer huge number of inputs, with 256 channel systems becoming increasingly common.

When choosing a multi-channel DAQ, it is important to consider how many channels you are ever going to need on one device. Whilst it can be tempting to go for a large number of input channels, devices with large numbers of channels are generally expensive, and may offer far more than you will ever need.

A second factor to consider is the type of data you will be feeding to your DAQ device. Whilst most of these devices now offer both analog and digital inputs as standard, in some cases each channel is dedicated to a particular type of input, limiting your usage of each.

Only after considering these questions, and having decided the number of channels you require, should you give consideration to other features of DAQ devices, such as the ability to wirelessly upload data, or the software included with them.

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What is the Cheapest Data Acquisition Available?

image showing the cheapest DAQ options

image of daq basics background

Choosing a data acquisition system (DAQ) can be a real task. In recent years, the explosion of devices on the market, each with their own advantages and disadvantages, means that any DAQ you are considering probably comes with a bewildering array of extra features.

Getting a DAQ need not be expensive, however, if you carefully consider what you need your system to do.

I would never recommend going for the cheapest DAQ available, for a number of reasons. Firstly, if you are using a DAQ to monitor a piece of machinery that you’ve spent many hours working on, you need a DAQ that is reliable. Your system overheating because your sensors have failed is frustrating, to say the least. Secondly, many of the cheapest DAQ systems on the market today are designed as discrete, proprietary units, meaning that they will not mesh well with the rest of your equipment, and will be difficult and expensive to expand.

Luckily all of Daqifi’s products are both affordable and extremely reliable. To see more please refer to our product pages.

That said, it is possible to achieve good value when purchasing a DAQ system, if you keep a few points in mind:

How Many Channels Do You Actually Need?

Whilst it may be tempting to go for a monster, 256-channel DAQ system, for most people and organisations this is more capability than they will ever utilize. Think carefully about the how much data you need to collect, and in what format, and buy a DAQ system accordingly.

Of course, you can always start with a small DAQ system, and then expand. Which brings me to my second point:

Go For a Modular System

The best DAQ systems available today are modular. This means that if you buy a device today, and then in a few years decide to add a second, they will work well together. This is perfect if you are using DAQ as hobbyist or semi-professional user, because it means that your DAQ system can expand as your passion does.

It also means that these systems work well with most third-party components, such as sensors and software. This can be a real advantage if you don’t have the time to be debugging each of your sensors.

How Are You Going To Collect Data?

The absolute cheapest DAQ systems on the market today output data via hardlink. The price of these systems might be tempting, but to my mind it is worth going for a system that is capable of sending data via Wi-Fi. You likely already have a Wi-Fi network in your workshop or home, and it makes sense to use it rather than building a whole separate system to handle your DAQ.

Get A System With A User Interface

Again, the cheapest DAQ systems around output data as a raw string of numbers. This is great if you are a software engineer, but for the rest of us means we have to learn a complex programming language.

The better DAQ systems come with on-board interfaces that allow you to collect and display data in an intuitive manner, and to my mind systems like this are well worth the extra investment.

So, whilst it may be tempting to go for the absolute cheapest DAQ system available, in my humble opinion you should always invest a little more in a few key features that will ultimately save you time and money.

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The End of DAQ Cards

why daq cards are dead

why daq cards are dead

DAQ cards were once the go-to solution for data acquisition systems. In the days when data acquisition was something of a niche activity, limited to high-end manufacturing and academic applications, often these cards were the only way of collecting and storing incoming sensor data.

If you’ve used DAQ cards, however, you are probably already aware that they suffer from some pretty major drawbacks. First and foremost among these are the price of dedicated DAQ cards, and the fact that in order to used them the user often needs extensive knowledge of proprietary programming languages.

In recent years, a new breed of data acquisition devices has appeared on the market, offering flexible data acquisition solutions that make implementing DAQ systems much easier. DAQifi devices are at the forefront of these innovative devices, and offer several huge advantages over traditional DAQ card implementations.

The Advantages of DAQifi Devices

DAQ cards typically output data using a dedicated hard link, and in years past this often meant having a separate PC workstation for every data acquisition process. Not only did this mean extra expense in terms of hardware, it often meant that bringing data from several processes together was a manual, painful business. DAQifi cards send the collected data over a WiFi network – either an existing one, or one generated by the device itself – to custom software.

What this means in practice is that a single PC, tablet, or even smart phone can be used to aggregate all the data being collected, bringing it all together for easy analysis and manipulation. This also means that the computer being used to collect and manipulate data does not need any additional hardware to be used for this purpose.

In addition, DAQifi devices represent better value than many DAQ card solutions. This is because DAQ cards are often made to be used to collect one type of data only, and in many cases this means that a bank of cards must be used in order to collect even quite basic data. The flexibility of DAQifi devices makes them cheaper to implement in many situations.

This is especially true in situations where portability is paramount. The fact that DAQifi devices run on their own power makes them ideal for situations where having a dedicated PC workstation is simply impossible. This is the case in many industrial processes, where the environment is not conducive to the health of computer hardware, and also in situations where the system under study is inherently mobile, such as in automotive engineering.

Lastly, the user interface which comes as standard on DAQifi devices means that using them is incredibly simple in comparison to many DAQ card solutions. Often, even in high-end scientific applications, all that is needed from a data acquisition system is for it to feed data to a centralized device, in a format which is easy to work with, for later analysis.

This is exactly what DAQifi devices achieve, and it is therefore not surprising that they are eclipsing DAQ card solutions in many situations.

To learn more about our products please click here.

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The Future of Data Acquisition Devices

Nyquist DAQ in action

Nyquist DAQ in action

The DAQifi Nyquist range of data acquisition devices are one of the best examples of a new breed of data acquisition devices.

In comparison to DAQ cards, these innovative devices offer a huge range of advantages. In high-end manufacturing and scientific processes, the ease of bringing together multiple data acquisition processes saves much time previously spent manually aggregating data.

In situations where space is tight, or the system under study is inherently mobile, the portability of these devices makes them ideal. And last but not least, the price of Nyquist devices means that they are within the budget of DIY hobbyists, who are therefore able to bring powerful data acquisition techniques to bear where this was previously thought impossible.

The Advantages of DAQifi Nyquist Devices

First, let’s take a look at what distinguishes DAQifi Nyquist devices from their primary competition – dedicated DAQ cards.

Perhaps the biggest advantage of these devices is that they utilize WiFi networks for outputting data. This has huge advantages over traditional DAQ cards, which typically have a hardware link to a dedicated PC workstation. If you want to collect data on various different processes, having your DAQ devices streaming this data to a central location is great, not least because it saves money on having to invest in separate computer hardware for every data acquisition process.

What this means in practice is that a single PC, tablet, or even smart phone can be used to aggregate all the data being collected, bringing it all together for easy analysis and manipulation. This also means that the computer being used to collect and manipulate data does not need any additional hardware to be used for this purpose.

In addition, the fact that Nyquist devices can generate their own WiFi network means they are enormously useful for situations where the system being studied is inherently mobile – as in race cars, for instance.

Using DAQifi Nyquist for DIY Projects

In DIY applications, these advantages can be supplemented by another – the fact that DAQifi Nyquist systems are significantly cheaper than dedicated DAQ card systems. This is because DAQ cards are often made to be used to collect one type of data only, and in many cases this means that a bank of cards must be used in order to collect even quite basic data. The flexibility of DAQifi devices makes them cheaper to implement in many situations.

In addition, the user interface which comes as standard on DAQifi devices means that using them is incredibly simple in comparison to many DAQ card solutions. No knowledge of proprietry data programming languages is needed, which is great for the DIY hobbyist. In contrast to high-end scientific applications, in most cases DIY data acqusition is about getting the relevant data into one place, quickly and easily, for later analysis.

This is exactly what DAQifi devices achieve, and it is therefore not surprising that they are eclipsing DAQ card solutions in many situations, from high-end manufacturing right down to amateur DIY projects.

To find out more about our products click here.

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DIY DATA ACQUISITION USING DAQIFI

DIY DAQ systems that work

DIY DAQ systems that work

Data acquisition is a critical part of many scientific, engineering, and academic systems and environments. If you’ve ever worked with systems like this, it is likely that you’ve come across a range of data acquisition systems.

It’s also likely that you’ve been frustrated with them. The typical forms of data acquisition system on the market today are expensive, awkward to use, and often require extensive knowledge of proprietary programming languages.

As a result, many processes that could benefit from data acquisition lack it, and many data acquisition systems in use are sub-optimal. Users can waste many hours configuring and troubleshooting data acquistion systems, leading to significant efficiency losses.

A New Breed of Data Acquisition Systems

In recent years, a range of novel approaches to data acquisition have been proposed. One of these is the DAQifi range of products. In contrast to the complex, embedded systems of the past, these new systems are built around modular, portable devices with in-built wireless connectivity.

These devices are stand-alone modules that plug easily into the system you wish to collect data on, and then stream this data over WiFi.

This brings huge advantages in many situations. Often, it is simply not practical to have a dedicated PC sitting next to your equipment. This is the case for many industrial processes that generate hostile environments for computers, and also in situations where the system being studied is inherently mobile, for instance in race cars.

Using DAQifi Devices for Data Acquisition

DAQifi devices can be used in a wide variety of applications. They are flexible and powerful enough to replace the complex data acquisition systems currently in use in industry and academia. I addition, the intuitive user interface and easy set up mean that even hobbyists can implement data acquisition into their DIY projects.

The modular devices plug straight into your sensors, and can be used to collect a vast array of different types of data – almost every variable there is a sensor for can be measured. The device then collects and stores this data, before sending it over WiFi. An existing WiFi network may be used, or the device can generate its own.

The dedicated software that is bundled with the devices can be used with PCs, tablets, or smart phones, giving the devices a great deal of flexibility. The user interface, in distinct constrast to many other data acquisition systems, is also easy to use.

Using this software, all the data being collected can be brought together into one place. This brings advantages not only in terms of the time saved in aggregating data, but also in allowing users to make an intuitive link between the various variables being measured.

DIY Data Acquisition

As a result of these innovative devices, collecting data on DIY projects is easier than ever. Whilst data acqusition systems used to be the exclusive purview of high-end manufacturing and academic research, it is now possible for hobbyists to implement data acqusition even on small systems.

To find out more about our products visit our products page.

 

 

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Data Acquisition for Race Cars

DAQ racecar driver

DAQ racecar driver

Data acquisition, for those unfamiliar with the term, is simply the process of collecting data on some physical process, and passing this data to a computer for analysis. Though most commonly used in industrial processes and scientific applications, there are many reasons why using systems like this can be useful for race cars.

First and foremost, implementing data acquisition systems in race cars provides a vast amount of data that can be invaluable in squeezing every last bit of performance from the vehicle. Formula One teams, for instance, employ dozens of people to analyze the torrents of data produced by their cars, in order to find out precisely where performance can be improved.

Before I take you through some of the other reasons to use data acquisition systems in race cars, it is worth noting that these systems are something quite different to telemetry. If you are involved with race cars in any way, it is likely that you are already used to using telemetry, and understand the key concepts of this.

Data acquisition is something different – whilst telemetry is typically used to improve performance during races or practice sessions, data acquisition produces data to be analyzed at a later date. Most commonly, it is used to improve mechanical performance of the race car itself, rather than that of the driver.

So what purposes can data acquisition be put to in a racing context?

Analyzing Vehicle and Driver Performance

Using Data Acquisition systems in race cars produces vast amounts of data that, when looked at in conjunction with telemetry, can be used to improve race performance. Collecting even the minimum level of data on in-race performance, such as RPM and engine temperature, can give valuable insights into where performance gains can be made.

 

Monitoring Reliability and Safety

Using data collected over longer periods can also be extremely useful in finding weak points in the reliability of vehicles. In fact, finding design weaknesses is almost impossible without collecting some form of data on how the vehicle was working during break downs.

In addition, using data acquisition on race cars can reveal potential failures before they happen. It might be the case, for instance, that tyre pressures are continually running near their design maxima, and that therefore tire failures are much more likely. Using data acquisition can reveal this before a catastrophic failure.

ASCERTAINING VEHICLE LIMITS

Using data acquisition techniques on race cars, it is possible to safely push vehicles closer to their limits. Analysis of data may reveal that certain components in the vehicle are capable of greater performance than is currently being wrung out of them, and that there is room to push them further.

In addition, analysis of this data can help drivers, by pointing out where they can push the vehicle further. Especially with unfamiliar vehicles, many drivers err on the side of caution, as they are unsure of the limits of the vehicle they are driving. Data acquisition for race cars can help them understand where these limits actually lie.

To learn more about DAQ products click here.

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PCI DATA ACQUISITION AND SIGNAL PROCESSING CONTROLLERS

PCI DATA ACQUISITION image

PCI DATA ACQUISITION image

Data Acquisition, in the broadest sense, is a process of collecting information on some real-world, physical system, and using this to analyze the system in question. In most cases, the system being measured is an industrial process or scientific experiment, and nowadays the data collected is almost always passed to some form of computer.

In recent years, the technology used to collect, process, and analyze such data is available off-the-shelf. In comparison to earlier systems, which were normally bespoke designs specific to a particular field or process, the use of off-the-shelf components means that they can be replaced easily and cheaply.

There are many factors to consider when designing and implementing a data acquisition system. First and foremost, the types of sensors used to collect data must be carefully though out. Secondly, the signal output by these sensors needs to processed into a form which is acceptable for a digital computer. Lastly, the software running on the computer being used to collect and analyze data must fit the purpose at hand.

For most engineers and scientists today, the standard choice of hardware is a PCI-based system. These systems use a standard connection between signal-collecting hardware and the hardware of the computer used to analyze this data. Though originally designed for the PC, in recent years PCI cards are available that will also work with Mac and other forms of computer system.

Today, I will give a quick introduction to the design and implementation of such systems, broken into the three main factors that must be thought about – the sensors used, the choice of signal processing controller, and the hardware and software required to work with the data collected.

Sensors

When designing and implementing any PCI data acquisition system, the first thing that must be considered is the type of sensors required. Whilst there are now sensors available for almost any kind of physical variable you wish to measure, it is worth noting that any sensor is likely to effect the operation of the system you are measuring, and it is therefore wise to use the minimum number of sensors required for your purposes.

In practice, this means carefully thinking through exactly the data you need to collect from the system you are interested in, and focusing on that type of data. Typically, one reading can act as a proxy for the total operation of the system – for instance, one of the most common variables measured by PCI data acquisition systems is temperature, which in many cases is used to indicate the smooth operation of industrial hardware.

Other examples of common phenomenon that measured by PCI data acquisition systems are light intensity, gas pressure, fluid flow, and force.

Signal Processing

Typically, PCI data acquisition systems use dedicated hardware to pass signals from sensors to the computer systems that will collect and analyze the data. Converting a messy, sometimes noisy, signal from a physical system into a format that can be used and manipulated on a computer can be a tricky business.

One of the first obstacles to be overcome in this regard is signal strength. As outlined above, typically sensors are designed to take the smallest amount of energy possible from the system they are being used to measure. In practice, this also means that the signal they output is of a vey low intensity, and must to amplified to be of any use.

It is therefore critical to use an amplifier that is able to amplify the signal cleanly. A noisy amplifier will ultimately warp and color the data collected, which in some cases can render it useless.

Another thing to think about when designing a PCI data acquisition system is the type of signal that you will use to pass data between the various parts of your system. Most sensors will output a single ended analog signal. Whilst this type of signal is good at capturing the raw state of the system being measured, it is also very susceptible to noise and distortion. A common fix for this problem is to convert the signal coming from the sensors into a differential signal, which is much more stable and easier to work with.

PCI Data Acquisition And Signal Processing Controllers

Once the signal has been amplified and cleaned up, it must be fed into a computerized system for collection and analysis. Nowadays, most data acquisition systems use standard PC hardware, meaning that if components of the system fail, they can be easily replaced with off-the-shelf items.

The most common format for getting an incoming signal into a computer nowadays is the use of PCI cards and other hardware. Though originally designed for PC, PCI cards compatible with many other systems are now available.

These external PCI cards are a solution to a common problem – that with complex data acquisition systems measuring many variables, the number of PCI inputs on a typical motherboard is too few. To work around this problem, an external card is used to combine multiple signals into a single input.

DAQ cards often contain multiple components that are able to perform signal processing before passing the signal to the software. In the most advanced cards, these functions are accessible via a bus by a micro-controller, though some cheaper systems used hard wired logic. For both types of card, proprietary device drivers are often needed.

These signal processing controllers are increasingly able to perform quite complex processing on incoming signals. For complex PCI data acquisition systems, this is invaluable for several reasons. First and foremost, it shifts the burden of signal processing away from the CPU, which in large complex systems can become choked by an overload of data.

The final stage in processing the signal is to pass it to software. Nowadays, a vast variety of different software solutions are available for use with PCI data acquisition system, and the choice of which to use depends on the type of data being collected and how it needs to be processed. Typically, however, such systems are based on commonly understood programming languages such as C++ or MATLAB, providing a large scope for customization.

Which to Choose DAQ Cards or DAQifi Products?

DAQ cards typically output data using a dedicated hard link, and in years past this often meant having a separate PC workstation for every data acquisition process. Not only did this mean extra expense in terms of hardware, it often meant that bringing data from several processes together was a manual, painful business. DAQifi cards send the collected data over a WiFi network – either an existing one, or one generated by the device itself – to custom software.

What this means in practice is that a single PC, tablet, or even smart phone can be used to aggregate all the data being collected, bringing it all together for easy analysis and manipulation. This also means that the computer being used to collect and manipulate data does not need any additional hardware to be used for this purpose.

In addition, DAQifi devices represent better value than many DAQ card solutions. This is because DAQ cards are often made to be used to collect one type of data only, and in many cases this means that a bank of cards must be used in order to collect even quite basic data. The flexibility of DAQifi devices makes them cheaper to implement in many situations.

This is especially true in situations where portability is paramount. The fact that DAQifi devices run on their own power makes them ideal for situations where having a dedicated PC workstation is simply impossible. This is the case in many industrial processes, where the environment is not conducive to the health of computer hardware, and also in situations where the system under study is inherently mobile, such as in automotive engineering.

Lastly, the user interface which comes as standard on DAQifi devices means that using them is incredibly simple in comparison to many DAQ card solutions. Often, even in high-end scientific applications, all that is needed from a data acquisition system is for it to feed data to a centralized device, in a format which is easy to work with, for later analysis.

This is exactly what DAQifi devices achieve, and it is therefore not surprising that they are eclipsing DAQ card solutions in many situations.

Read more about this in our DAQ vs DAQifi post.

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Types of Data Acquisition Systems

types of DAQ systems

types of DAQ systems

Data Acquisition Systems, often abbreviated to DAS or DAQ, are systems designed to measure and track some form of physical system, and convert this data into a form that can be viewed and manipulated on a computer.

The design an implementation of DAS is a complicated field. The first DAS were designed by IBM back in the 1960s, and were huge assemblages of computers and hardware. As the field has developed, more generic systems have become available, and accordingly it is now possible to measure and analyze almost any form of physical system.

DAS are now used in many different fields, from industrial production to scientific experiments, and the type of system used is different depending on each application.

In general, however, types of DAS can be broken into three components – the sensors used to collect data from the physical systems, the circuitry used to pass this data to a computer, and the computer system on which it can be viewed and analyzed.

If you are setting up a DAS, these are also the three factors that should be considered. Time spent thinking about exactly which data you need to collect, and how you want to work with the data once it is collected, can save significant time and money further down the line.

Let’s take a look some of the most common options in all three of these fields.

Sensors

The design of any DAS must start with the physical system which is being measured. With the range of sensors available today, it is possible to measure almost any physical property of the system you are interested in. Careful consideration must be made, therefore, of exactly the type of data you need to collect. It might be nice to be able to track the temperature of your industrial printer, for instance, but you need to think about whether this information will actually be useful for you.

Examples of common phenomenon that are measured by DAS are temperature, light intensity, gas pressure, fluid flow, and force.

For each variable to be measured, there exists a particular type of sensor. Sensors, in this sense, are essentially transducers, transforming physical energy into electrical energy. For instance, a basic pressure sensor will be activated and driven by the pressure it is measuring, and pass this information as an electronic signal to the DAS.

For this reason, it is important to recognize that it is not possible to measure every variable you want to without effecting the system itself. This is because any sensor will effect the system it is designed to measure, and remove energy from it. This is especially important if the system being measured works on small tolerances, because the addition of even a small sensor to these systems can drain too much energy from them for effective operation.

In short, though there is likely a sensor available to measure almost any aspect of your systems, it is not always wise to try and measure every variable. Instead, think carefully about the data you actually need, and use the minimum number of sensors that will achieve this.

Signal Processing

Typically, DAS use dedicated hardware to pass signals from sensors to the computer systems that will collect and analyze the data. Converting a messy, sometimes noisy, signal from a physical system into a format that can be used and manipulated on a computer can be a tricky business.

One of the first obstacles to be overcome in this regard is signal strength. As outlined above, typically sensors are designed to take the smallest amount of energy possible from the system they are being used to measure. In practice, this also means that the signal they output is of a vey low intensity, and must to amplified to be of any use.

It is therefore critical to use an amplifier that is able to amplify the signal cleanly. A noisy amplifier will ultimately warp and color the data collected, which in some cases can render it useless.

Another thing to think about when designing a DAS is the type of signal that you will use to pass data between the various parts of your system. Most sensors will output a single ended analog signal. Whilst this type of signal is good at capturing the raw state of the system being measured, it is also very susceptible to noise and distortion. A common fix for this problem is to convert the signal coming from the sensors into a differential signal, which is much more stable and easier to work with.

Computer Hardware and Software

Once the signal has been amplified and cleaned up, it must be fed into a computerized system for collection and analysis. Nowadays, most DAS use standard PC hardware, meaning that if components of the system fail, they can be easily replaced with off-the-shelf items.

First and foremost, the signal must be converted into a digital format that the computer understands. Typically, this is done using the pre-existing ports on a PC, such as the parallel ports, USB, etc. Another approach is to use cards connected to slots in the motherboard. With this second approach, a common problem is that the number of ports on a PCI card is too few to accept all of the inputs needed. To work around this problem, a breakout box is used to combine multiple signals into a single input.

DAS cards often contain multiple components that are able to perform signal processing before passing the signal to the software. In the most advanced cards, these functions are accessible via a bus by a microcontroller, though some cheaper systems used hard wired logic. For both types of card, proprietary device drivers are often needed.

The next stage in processing the signal is to pass it to software. Nowadays, a vast variety of different software solutions are available for use with DAQ, and the choice of which to use depends on the type of data being collected and how it needs to be processed. Typically, however, such systems are based on commonly understood programming languages such as C++ or MATLAB, providing a large scope for customization.

Despite these changes, the data acquisition market has changed and DAQ Cards find themselves increasingly an obsolete form of DAQ. Newer devices that allow for more robust feature and capabilities while not being limited by fixed cards are now starting to dominate the market.

The Advantages of DAQifi Devices

DAQ cards typically output data using a dedicated hard link, and in years past this often meant having a separate PC workstation for every data acquisition process. Not only did this mean extra expense in terms of hardware, it often meant that bringing data from several processes together was a manual, painful business. DAQifi cards send the collected data over a WiFi network – either an existing one, or one generated by the device itself – to custom software.

What this means in practice is that a single PC, tablet, or even smart phone can be used to aggregate all the data being collected, bringing it all together for easy analysis and manipulation. This also means that the computer being used to collect and manipulate data does not need any additional hardware to be used for this purpose.

In addition, DAQifi devices represent better value than many DAQ card solutions. This is because DAQ cards are often made to be used to collect one type of data only, and in many cases this means that a bank of cards must be used in order to collect even quite basic data. The flexibility of DAQifi devices makes them cheaper to implement in many situations.

This is especially true in situations where portability is paramount. The fact that DAQifi devices run on their own power makes them ideal for situations where having a dedicated PC workstation is simply impossible. This is the case in many industrial processes, where the environment is not conducive to the health of computer hardware, and also in situations where the system under study is inherently mobile, such as in automotive engineering.

Lastly, the user interface which comes as standard on DAQifi devices means that using them is incredibly simple in comparison to many DAQ card solutions. Often, even in high-end scientific applications, all that is needed from a data acquisition system is for it to feed data to a centralized device, in a format which is easy to work with, for later analysis.

This is exactly what DAQifi devices achieve, and it is therefore not surprising that they are eclipsing DAQ card solutions in many situations.

Read more about this in our DAQ vs DAQifi post.