What are the considerations you should have when deciding what data acquisition method to use on your investigation?
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A data acquisition system plays quite a vital role in the collection of data from any process that is ongoing. The data so collected provides the users with the required information so as to clearly understand the performance of the overall process along with the steps or areas that require improvement. So, it becomes extremely important to incorporate these systems into the process for better results. Now, the confusion that arises here is the choice of the system for the purpose of acquiring data. So, for the selection of the appropriate data acquisition system, considering a few of the important factors would be ideal. Please read through to find the important factors to consider at the time of setting up the data acquisition systems. Show
TimeFirst and foremost, you need to be clear about the duration of time for which you want the system to run without interruption. This time duration will make a significant impact on the choice of the hardware as well as the operating system. In an addition to this, if the processor gets stressed in continuously keeping up with the tasks, then there are high chances that the data flow might get backed up along with errors as a result of buffer overflow. The hard drives of the system are spinning which starts wearing out and also the time battery of the internal battery will stop functioning after a decade or earlier. So, the first thing to consider would be the time you want the system to run which in turn would allow you to make the right selection. Source of PowerThe next thing to consider is the source of power. You need to see whether the system will have an access to a source of power or if it needs its own power source. If the system for data acquisition has an access to the prime power, then it becomes much easier than supplying your own portable power of your own such as from a battery, solar panel, etc. The calculations of power, as well as energy utilisations, might be tricky for multi-mode operations. So, it is ideal to be conservative and take the measurements of power under the real-world conditions of operating. Transmission of DataThe next thing to consider is the transmission of data from the system. You need to be sure whether the data acquisition system needs to transmit data remotely from the field or the plant or only local data storage is enough. This would help you in choosing the appropriate system. In an addition to this, you need to make sure whether you want the system to have the capability of storing & forwarding for the purpose of buffering the acquired data when the link is not available and continue to send when it is back online. Moreover, you need to decide on the storage you require and select the system as per that. Access to the SystemAt the time of setting up a data acquisition system, you need to be clear about the fact that you need access to the system remotely for configuring it or checking its status or not. It also might happen that you need the acquisition parameters of the system to be modified for which access to the system is essential. Thus, you should be setting up a system for data acquisition that can be accessed remotely. Data Acquiring and ProcessingWhen you have planned to set up a data acquisition system, you need to decide beforehand whether you simply need to acquire raw data or you need the acquired data to be processed in some specific way after the acquisition process. Considering this factor is of immense importance in selecting the right system for data acquisition. If you simply need to acquire data from the process, a simple system would be sufficient. But in case you need the system to do some specialized tasks such as filtering, windowing, and other processes it would be requiring a CPU in the system to perform the tasks effectively. Channels of InputFinally, you need to check you channels of your input which would necessarily be a great determining factor where you need to be sure as to how your input channels look like. The driving factors to consider here are the sample rates, the channels or signals from which the data is to be acquired, the range of signals, and the synchronization. Considering all of these factors would enable you to choose the most appropriate data acquisition system. Now, when you intend to set up a data acquisition system, you need to make sure to choose a trusted and reputed manufacturer like Gtek. With several years of experience in this field, Gtek would undoubtedly be the best choice in the case of data acquisition systems. Choosing the right data acquisition system can be a challenge for even the most experienced test and measurement engineers and technicians. There are several important factors that must be taken into consideration during the DAQ selection process. This article will guide you through the process in a logical way, then present you with a software tool that we have invented that automates the selection process. 5 Essentials When Choosing Data Acquisition HardwareTo jump right in, these 5 metrics are essential when choosing correct data acquisition hardware: Scrolling further down we will break down all important questions you need to ask yourself in order to choose the best data acquisition system for you.  Which Questions Do You Need to Ask Yourself When Choosing Right Data Acquisition System?Technical Considerations and Compatibility To Your ApplicationEase of Use, Features, and SupportInvestment Cost and Cost of the Ownership ConsiderationsTechnical Considerations and Compatibility To Your Application What Analog Signals/Sensors Do I Need to Measure?The essential function of a DAQ system is to make measurements from various sensors and electrical signals, e.g. to measure some kind of physical phenomenon. Therefore, making a comprehensive list of the types and quantities of signals and sensors that you need to measure is the first thing that you should do. This information will drive everything that follows. There are numerous sensors and transducers for measuring temperature, vibration, pressure, strain, voltages, currents, resistance, and many more. Learn more: Strain Measurement Using Strain Gage Sensors What Digital Signals and Bus Data Do I Need to Record?Today’s DAQ systems can measure much more than analog signals like voltages and temperatures. There are digital signals from encoders, RPM sensors, gear tooth, and tacho sensors, for example, that require a different kind of input. These “counter” inputs must be sampled much faster than the analog inputs. There are also digital bus data that can be displayed and captured from the CAN bus found in every car and truck, data transmitted across RS232 and Ethernet interfaces, position data from GPS sensors, and 3D orientation data from IMU (inertial measuring units), EtherCAT data found in countless industrial and process control environments, ARINC 429 and MIL-STD-1553 bus data found in commercial and military aircraft, and more. Do you need to capture data from any of these? There are industrial video cameras that can capture video in sync with your other data. Is this a requirement for you? Will it be in the future? Learn more: What is CAN bus and how does it compare to other Automotive interfaces What Measurement Resolution do I Need?The most common measurement resolution today is 16-bit, but there are higher-end DAQ systems that provide 24-bit resolution, which is considered essential especially for noise and vibration applications, and 12-bit resolution systems for low-end data logger applications. Each bit doubles the possible resolution of the DAQ system. That means that 24-bit is not just 50% more resolution than 16-bit resolution. In fact, 24-bit ADCs provide 256 times greater possible resolution than 16-bit ADCs. Theoretical maximum values based on bit resolution: Number of BitsMax Values12-bits 4,096 14-bits 16,384 16-bits 65,536 24-bits 16,777,216 How Much Dynamic Range Do I Need? 80 dB, 100 dB, 130 dB, or 160 dB?Dynamic range is the difference between the smallest observable part of the signal and the largest. Systems that have higher dynamic ranges provide more vertical axis resolution. Another way of looking at this is to ask this next question… What Is The Smallest Change In a Measured Signal that I Need to Detect?This goes hand-in-hand with dynamic range. You should have an idea of the smallest change in a signal that you want to see. Systems with the highest dynamic range provide the best possible vertical axis measuring resolution. But you also have to consider the time axis, because if changes in amplitude fall between samples, they cannot be measured. Systems with greater than 100 dB dynamic range and at least 200 kS/s sample rate can handle most applications. For shock, noise, and vibration applications, a dynamic range of 120 to even 160 dB is highly desirable. Our DualCoreADC® technology in the SIRIUS data acquisition systems boosts dual 24-bit delta-sigma ADC converters with an anti-aliasing filter on each channel. This allows our DAQ modules to achieve an astonishing 160 dB of dynamic range in the time and frequency domains. Along with up to 200 kS/s/ch sampling rate per channel, these are unique amplifiers on the market. What Level Of Accuracy Do I Need?In an ideal world, measuring systems would be 100% accurate, but perfection is not really possible. There will always be some inaccuracies introduced into the measurement chain, starting right at the sensor itself. The most common factors contributing to the inaccuracy of any measuring system are gain errors, offset errors, and temperature drift errors in the analog domain and the time base accuracy of the ADC (analog-to-digital converter) and digital counters. A good DAQ system will specify its accuracy in a clear and consistent way. For example, time base accuracy is normally expressed like “Typical 5 ppm, Max: 12 ppm,” meaning that the oscillator might typically deviate from its nominal value up to 5 parts per million, but the maximum deviation is 12, in this example. Gain accuracy is normally written as a percentage, like: “±0.05 % of reading.” So if the system is reading +1.000 V, the gain error could be as much as ±0.0005 V. It can also be written as a percentage of full-scale. Offset accuracy is written as an absolute value, like “±0.02 mV,” which is easy to understand. Temperature drift can affect both the gain and offset accuracy. Gain temperature offset is written like “±50 ppm/K of reading ±200 μV/K,” for example. This ties the error directly to the change in ambient temperature, in Kelvin. What Kind of Noise Performance Do I Need?You’re probably thinking “I don’t want any noise!” Of course not, but in the real world, electrical and magnetic “noise” is bombarding DAQ systems constantly. Even when they are shielded properly, sensor cables are like antennas. In addition, there are nearby sources of EMI and RFI in most DAQ measuring environments. The key is to find the system with the best isolation and the best grounding practices. Please see the next question for more details about isolation. Does My DAQ System Need Isolation?Electrical galvanic isolation is important for safety, for example, when you’re dealing with high voltages. But it also preserves the integrity of all measured data regardless of voltage level, by eliminating or reducing noise, crosstalk, and ground loops, which can either obscure or completely destroy your measurements. Channel-to-channel isolation means that the noise or crosstalk between and among all channels is prevented. Input-to-output isolation means that whatever the sensor or measuring wire is connected to in the outside world is isolated from the DAQ system. Systems with both channel-to-channel and input-to-output isolation provide the most robust isolation. SIRIUS DAQ systems from Dewesoft provide both channel-to-channel and channel-to-ground isolation, as shown in this short video: Learn more: The Importance of Isolation in Data Acquisition Systems Do I Need Filtering Capabilities?Filtering is one of the most important elements of analog signal conditioning. Filtering allows you to reduce or completely block frequencies above or below a selectable frequency component from being recorded. There are also band-pass and band-stop filters, allowing you to select a certain range of frequencies for inclusion or exclusion. Common analog filter types Filtering is sometimes needed to block 50 or 60 Hz noise created by nearby electrical power systems, or higher frequencies from electromotors, generators, power supplies, fluorescent lights, etc. There are many sources of electrical noise that can interfere with your measurements. Ask yourself if you need non-destructive filtering. Would it be helpful if the filters applied before recording could be removed afterward, or changed completely? Dewesoft systems have this capability. Do I Need Anti-aliasing Protection?An “alias” is a false signal that is created when the signal is moving too fast compared to the sample rate. Aliasing must be prevented before the measurement is made, otherwise, there is no way to recreate the real signal later. There are two ways to prevent aliasing:
Any DAQ system that is used for noise, shock, and vibration, or applications that involve AC waveforms should have robust, completely automatic anti-aliasing built-in, to ensure the integrity of your measurements. Learn more: What is ADC (analog-to-digital converter)? How Fast Do I Need to Acquire or Sample the Signal?The job of a DAQ system is to reproduce the character of the signal with as much fidelity as possible. A good rule of thumb is to pick a system that is capable of sampling at least 10 times faster than the fastest signal that you need to capture. For example, if you need to capture signals that have 20 kHz content, your system should be capable of sampling at 200 kHz. You might read that you only need 2x over-sampling, i.e., the Nyquist frequency. Just note that only 2 samples per period cannot reproduce the appearance of the waveform. The new HybridADC technology developed for the SIRIUS XHS product line allows the user to select three modes of operation, depending on the selected acquisition rate:
Dewesoft data acquisition technologies explained The Next Generation Power Analyzer with SIRIUS XHS Should My DAQ System Be Upgradeable or Expandable to Meet Future Needs?Most engineers have a limited budget every year, and they tend to favor systems that are easy to upgrade or add on to, next year, and in the years that follow. Product lines that are built around a common “ecosystem” are easily interconnected and share modular elements. They can be synchronized together easily. They share a common software platform that integrates them all and eliminates having to learn to use completely different systems. When looking at a manufacturer’s offerings, find out if they are built around such an ecosystem: can you interconnect them, and do they share common hardware and software? Dewesoft data acquisition systems are modular by design. The input channel count and configurations can grow together with your testing need so you can easily expand the entire testing system at any time. Do I Need a Portable, Benchtop, or Rack-mounting System?This should be easy to analyze - it’s all about the environment that the DAQ system is expected to work. Certainly, any mobile environment, like inside a car, truck, train, etc., requires a portable system. Besides being generally smaller and lighter, portable systems typically run from either AC or DC power, so that they can be easily powered inside vehicles. Many of them also run from internal batteries, making them ideal for fieldwork. Battery-powered data acquisition systems have the added advantages of having a built-in UPS, and they don’t draw on the power system if that’s what you’re trying to measure. If your environment is a nice clean laboratory or manufacturing floor then a benchtop system is generally fine. Benchtop systems are typically AC-powered and are larger than portable ones. If you intend to permanently mount your system in a 19” rack enclosure, then a rack-mounting system makes the most sense. Dewesoft provides all kinds of data acquisition systems from handheld, benchtop, portable, to rugged, and high-channel rack-mounting systems. DEWE-43A handheld DAQ system SIRIUS modular and portable DAQ system SIRIUS R2DB portable all-in-one DAQ system SIRIUS R4 benchtop DAQ system SIRIUS R8DB high-channel-count portable all-in-one DAQ system SIRIUS R8 bench-top high-channel-count DAQ system SIRIUS R3 rack-mountable DAQ system KRYPTON rugged, distributed DAQ system IOLITE LX embedded DAQ system IOLITE R12 rack-mountable industrial DAQ system IOLITE R8 portable industrial DAQ system IOLITE DIN rail-mountable industrial DAQ system Do I Need a Stand-alone Instrument, Or Should It Be Connected to a PC?This is a matter of your preference. PC-connected DAQ systems have the advantage of being smaller because they don’t have a computer, display, or hard disks inside of them. They are generally less expensive for the same reason. And, you can use your own computer. But if you’re going to have to leave the system in a non-secure environment, a stand-alone system might be a better choice. Do I Need a Rugged System That Can Withstand Heavy Shock or Vibration?If you’re bouncing around in cars and trucks, for example on test tracks, then there’s going to be a lot of shock and vibration. You know your environment better than anyone, so you probably already know the answer to this question. It’s something worth thinking about. Most DAQ systems are not designed for high shock and vibration environments. Always check the shock and vibration ratings. Systems rated in the 100 g range (EN 60068-2-27:2009) are considered rugged. Vibration is also a factor, particularly random vibration. Systems tested to MIL-STD-202G Method 214A, test condition II-D and above are considered rugged. Dewesoft DAQ systems are extensively tested in our state-of-the-art testing labs for shock and vibration. We install our systems on rocket launch platforms, use them in off-road proving grounds and all other types of environments where high ruggedness is needed! Do I Need a System With a Wide Temperature Range or One that’s Dust-proof or Waterproof?Another question worth thinking about is operating temperature, dust, and water protection. Environmental testing either in nature or in chambers always requires systems that can tolerate a much wider range of temperatures found in factories and laboratories. Field testing of any type when you’re taking the instruments outside can lead to temperature extremes. It can also lead to salty air, heavy humidity, fog, dust, and even rain. If this is your working environment, then a system rated to IP65 or IP67 is a very good idea, since it will be sealed against the ingress of particles, including water. Systems rated to IP67 and with operating temperatures from -40° to 80°C (-40° to 185°F) provide excellent water and particle ingress protection and temperature performance. KRYPTON and SIRIUS Waterproof are ultra-rugged DAQ systems for field testing in harsh environments that provide a wide operating temperature range, waterproof, and high shock protection. Are the System’s Specifications Easy to Understand?DAQ manufacturers vary in terms of how much and which information is provided within their specifications. In addition to performance characteristics like a number of channels, selectable gain ranges, top sample rate, et al, it’s important to look at the accuracy and isolation specifications. It’s easy to be impressed by specification numbers with lots of precision, but that’s not the same thing as accuracy! For example, if you specify that the time is 2:00:0006437 PM, but it’s really 3:15 PM, that’s a lot of precision, but very poor accuracy. It’s a good idea to look at how consistent specifications are given across different signal conditioners, for example. Is isolation of 1000V shown on several modules, but not mentioned at all with other signal conditioners? That could be a red flag. Always make sure that you know what the most important specifications to you really are, and how they apply to all important aspects of the product. Ease of Use, Features, and Support Are Operation Manuals Available and Easy to Read?It’s great to have an operating manual, but only if you can understand it. It should be well-written in your language, and clear. Ideally, the manual will also be available as a searchable PDF file or even available online as a website with extensive search features. And a great convenience is HELP built right into the software itself. When running the DAQ software, does pressing F1 brings up context-sensitive help based on what you’re doing in the software? Is it searchable? Does it contain the entire manual? Also check if there are any other training resources available like webinars, online training courses, how-to guides, that will help you achieve your goals. Check out also: Download Dewesoft hardware manuals What Technical Support Is Available to Me?It’s always a good idea to ask about what kind of support you can expect after receiving your new DAQ system:
You get the idea. No one expects all of these things to be free, but they should be available and performed at the most professional level, with a focus on you, the customer. Dewesoft offers a FREE global and local technical support line for our data acquisition solutions. Contact Dewesoft technical support Is The User Interface Easy to Read and Learn?This might be the most important thing to investigate before buying any DAQ system. Ideally, you will have had a product demonstration, but in addition, it should be possible for you to download the software and run it in a demonstration model on your own computer. Always ask for this, so that you can get the feeling of the interface, and gauge how long it will take you to achieve basic proficiency. DewesoftX data acquisition software offers a very intuitive user interface with a short learning curve and no need to program in order to get great signal processing results. It really makes using the data acquisition system enjoyable again. Is the System Easily Reconfigured for Different Applications?It is a great probability that you will need your DAQ system for different measurement tasks and applications. System reconfiguration to fit your certain task may involve both hardware and software. For example, if your DAQ system has plug-in signal conditioning modules, you may need to exchange some of them for different measurements. Is this easy to do in the hardware, and does the software automatically recognize the new modules? Or, you may need to connect an external module or system to your main one - is this also easy to do? Does the software see the new channels and configure them in the software? Is synchronization handled? Can I Save Setups for My Applications?The ability to freely name and save an unlimited number of setups should be a basic function of any good DAQ system. However, it’s always a good idea to check that this is supported, and how it is implemented. This will save you a lot of testing preparation time and will enable you to easily repeat frequent measurements. Can I Analyze My Data on the DAQ System? Can I Also Analyze Offline?Most DAQ systems provide some level of built-in data analysis that can be performed after the data has been acquired. It’s a good idea to find out exactly what can be done. For example, if filtering was applied during measurement, can it be changed or even removed afterward? Can you create math functions and then run them on the recorded data? Can you make new displays and compare data easily? Does the DAQ system allow you to put this software on your own computer and do all of these same analytical functions? Is it free of charge or are you required to have a paid license or a hardware dongle? Can the software be installed on other computers as well, either for free or with a paid license? Obviously, you’d probably like to be able to do all of these things, and without any fees. But some DAQ makers do charge for this, so you should find out ahead of time. Can Data Be Exported Easily to Other Analysis Programs?Unless your data will never require analysis outside of the DAQ system itself, it should be possible to export it in one or more common data formats. It should also be possible to select a portion of the data for exporting, and which channels are to be included. Common data analysis formats include:
But there are many more, so you should verify that your DAQ system supports the specific format that you need. Also look at the import capabilities of your analysis software, because many of them can accept a number of file types. Learn more: Exporting data and supported file formats in DewesoftX DAQ software Which Analysis Programs are Supported?As mentioned above, if there is a particular data analysis program that your company is using, you should verify that your DAQ system is capable of exporting to it. The most popular analysis programs include Excel® for limited data sets and Flexpro® and Matlab® for virtually unlimited data sets and a wide array of built-in analytical functions. But there are other programs on the market. Some companies have even developed their own analysis tools in-house, and these are written to accept various file formats, almost always including a basic text format for universal compatibility. Learn more about the DewesoftX data analysis features. DewesoftX data acquisition software includes in-depth math for digital signal processing in a single software package. Investment Cost and Cost of the Ownership Considerations Is Data Acquisition Software Included or Do I Have to Pay Extra?Some companies offer attractive pricing on their data acquisition hardware. But you need to be careful and check if the software that enables you to use that DAQ hardware is included in the offered price. Also, make sure you know your software requirements! Check if the features you require are included in the included software package or require any upgrade options. Are those for free or require extra investment? DewesoftX software is always included for FREE with all of our data acquisition systems. Are Software Updates Free, or Will I Have to Pay for Them?Software is never “done” - it’s always being improved and developed. There will be new releases that not only correct bugs but which add important new features and capabilities. The majority of data acquisition companies require you to subscribe to an annual support contract, either for the software itself or for the entire system. This cost is often calculated as a percentage of the overall system cost. Or, they charge for new releases. Dewesoft considers the software to be an essential living part of the data acquisition system and does not charge for its updates and new releases. All releases are free forever for all existing customers. Dewesoft releases 4 major software releases each year, adding new features, performance optimizations, new device support, and bug fixes. DewesoftX software offers FREE lifetime updates for all existing Dewesoft users. Check out release notes and the features added in the last SW releases. All these features are available for FREE by downloading our latest DewsoftX installer. DewesoftX 2021.6 release Is There an Annual Maintenance Fee?One of the “hidden” costs of owning a DAQ system may be an annual maintenance fee. You should ask right up front if there is a mandatory maintenance fee, and if so, what does it include and how is it priced? Ideally, there will not be one, but you should know upfront before you order the system, because it is an expense that will have to be budgeted ahead of time.
Dewesoft data acquisition systems do not require any yearly maintenance fees, except for recalibration if your company policy demands a recalibration of the systems on yearly basis. How Much Does Calibration Cost? What Is Included?All measuring systems require calibration. You might assume that a brand new system would arrive fully calibrated from the factory, and that “traceable” calibration certificates would be included. Don’t take that for granted and verify that with the manufacturer. If they include them, that’s great. If not, how much do they cost? Now, what about next year? And the year after that? Calibration is normally only valid for one year, so you should find out what your options are for future calibration. If your company has a calibration lab, they may be able to purchase a calibration kit from the DAQ manufacturer that will allow your company to do calibration in-house. If not these are things to reconsider:
All Dewesoft data acquisition systems are calibrated and checked for conformance tests before they leave our headquarters to you. Dewesoft has local factory calibration labs in Austria, Brazil, China, France, Germany, Hong Kong, Russia, United Kingdom, Sweden, The United States of America. For more information see our DAQ Calibration Services page. How Long Is the Warranty?The warranty period is another important thing to know about. One year is a good length for a warranty from the manufacturer, and Dewesoft includes this as standard. When comparing DAQ systems you should always ask about the warranty and what it provides. Dewesoft offers an industry-leading 7-year warranty for its data acquisition systems. During the 7-year warranty period, Dewesoft guarantees to keep your equipment in working order by repairing or replacing it. The Dewesoft 7-year warranty is valid worldwide, no matter where the equipment is located. There are no hidden service costs or maintenance fees. For more information check the Dewesoft Warranty page. What Technical Support Is Available and for What Cost?Like already answered earlier above in the question What Technical Support Is Available to Me? Good technical support is essential when it comes to data acquisition and similar systems. Ask yourself those questions. If technical support is available it is usually not free. Double-check the cost associated with it to see what cost could arise during the lifetime of your data acquisition system. What are the four different methods for acquiring data?There are four methods of acquiring data: collecting new data; converting/transforming legacy data; sharing/exchanging data; and purchasing data. This includes automated collection (e.g., of sensor-derived data), the manual recording of empirical observations, and obtaining existing data from other sources.
What are the two types of data acquisitions in digital forensics investigations?We are going to look at two types of forensic acquisitions – a logical acquisition and a physical acquisition. For our example in this article the device we need to image is a USB drive.
What are the acquisition methods in digital forensics?The four methods of acquiring data for forensics analysis are disk- to- image file, disk-to- disk copy, logical disk- to- disk or disk- to- data file, or sparse data copy of a folder or file. Large disks might require using tape backup devices.
Why data acquisition is important in digital forensics investigations?The gathering and recovery of sensitive data during a digital forensic investigation is known as data acquisition. Cybercrimes often involve the hacking or corruption of data. Digital forensic analysts need to know how to access, recover, and restore that data as well as how to protect it for future management.
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