A ScopeCorder is a powerful portable data acquisition recorder that combines features of a multi-channel digital oscilloscope and a high-performance oscillographic recorder. As such, it can capture and analyze both short-term transient events and long-term trends for periods up to 200 days.
Using flexible modular inputs, it combines measurements of electrical signals, physical (sensor) parameters and CAN/ LIN serial bus signals. It is able to trigger on electrical power related events and carry out calculations in real-time.
A ScopeCorder is often perceived by users as one of the most powerful portable data-acquisition instruments available on the market today. It has several unique features that offer users of other types of measuring instruments - such as recorders, data loggers, oscilloscopes, and power measuring devices – an alternative measuring method to consider for their applications.
Whether the measurement signals are derived from the smallest electric drives incorporated in a precision watch, a large turbine found in a power generating facility, sensors and electronics found in a modern electric vehicle, or from household appliances, the features and flexibility that come with the ScopeCorder offer value to all these applications.
This application note discusses the top 10 reasons, plus one, to select a Yokogawa ScopeCorder.
The ScopeCorder’s modular design allows users to choose from a range of over 20 types of input modules, each with built-in signal conditioning, and install up to eight of these modules in the instrument at any time.
This setup allows measurements on up to 128 channels with a mixed selection of data-acquisition cards to measure parameters such as:
The flexibility of this modular platform enables the ScopeCorder to be configured to perfectly suit the requirements of the application. Moreover, the measurements on the input channels are time-synchronized, which allows the user to easily find relationships between different measurements.
The majority of engineers using a ScopeCorder for their applications claim that input channel isolation is a key benefit to their measurements. Channel isolation allows measurements to be carried out on floating signals or to measure at different points of a circuit, where the grounds of those points are at different potentials, without having to use any special differential probes.
The housing for the input modules includes both shielding for the single input channel and extra shielding for the housing of the input module. Using this double shielding method with the input channels inside the input modules results in high noise rejection.
Many applications include measurement signals coming from frequency inverters, possibly in combination with temperature measurement. In order to develop these high-efficiency inverters which employ high voltages, large currents, and ever-increasing switching speeds, a special input module incorporating Yokogawa’s iso-PRO™ core technology is used, ensuring fast data transmission (Max 200 MS/s) and industry leading isolation to the input elements. Using internal high-speed optical fiber-based transmission, this module achieves high sample rates and high resolution (up to 16 bits), and provides the performance needed for precise measurement of fast switching signals even in the harshest environments.
A ScopeCorder is equipped with a large and fast acquisition memory of up to 2 GPoint capacity, which enables high sample rates on multiple channels simultaneously. This high sample rate, in combination with a high vertical resolution of the A/D converter (either 12 or 16 bits), is ideal for precisely capturing waveform details. However, when involved with durability testing over longer periods of time – for example, days or weeks – data is typically acquired at lower sample rates. Allowing a lower sample rate does not increase the size of the measurement files unnecessarily, and is sufficient to visualize long-term trends. On the other hand, suddenly occurring transitional phenomena have to be captured at high sample rates in order to view the detail and to be able to investigate the particular event.
The ScopeCorder’s “dual capture” function uniquely resolves these conflicting requirements through the ability to record at two different sampling rates.
As an example, it is possible to set waveform triggers and capture 5000 high-speed transient events at 100 MS/s while at the same time continuously recording a trend measurement at 10 kS/s for 10 hours.
For engineers, it is possible to reduce time spent on fault-finding or transient analysis when it is possible to easily visualize the disturbing event on a signal. The key question here is how to determine whether there is a transient event.
The ability to set a broad variety of triggers on multiple channels provides the power to investigate the causes of particular transient event. Moreover, the availability of the ScopeCorder’s large acquisition memory, and thus the ability to measure over longer time periods, helps the analysis of the effect of such an event on other parts of the application by investigating other measurement channels’ behavior after the trigger event.
A ScopeCorder is sometimes referred to as “the ultimate trigger machine,” and is packed with basic and enhanced triggers. A feature called “action on trigger” allows the user to leave a ScopeCorder unattended and automatically save the waveform to a file or send an email for notification of a trigger event.
A data acquisition recorder, which can display up to 200 days of recording on its screen, is only practical when the user can seamlessly zoom into all the waveform details. The ScopeCorder allows users to rapidly zoom in to view two billion samples. Each ScopeCorder is equipped with the Giga Zoom Engine, a powerful processor designed for optimizing access to data seamlessly. It is possible to activate two zoom windows while displaying the entire original signal. In this way, an engineer can observe long-term recordings while also zooming into every detail of the waveforms – for instance, to observe and analyze transient events.
Analysis after the measurement can be done on the instrument itself, in the Yokogawa Xviewer waveform analysis software, or using third-party analysis software. Whichever procedure is used, a quick reading of values such as amplitude, peak values or frequency is often required on the instrument itself. In this case, the ScopeCorder offers a range of convenient analysis functions including parameter measurements and cycle statistics.
Horizontal or vertical cursors provide a quick and easy method to measure waveform parameters on the screen. However, the ScopeCorder offers another faster way to automatically display the measured values after the measurement has been completed. This feature is the automatic waveform parameter measurement. The parameter measure function is the most precise method for automatically calculating any or all of the 28 different waveform parameters such as amplitude, peak-to-peak values, rms, risetime, frequency, and more.
Sometimes when observing a waveform with multiple events or periods, such as a sine wave, pulse train, or PWM signal, statistical calculations are required to check, for instance, which period has the highest amplitude or contains the most energy. The ScopeCorder has a powerful cycle statistical function that automatically measures selected parameters individually for each waveform cycle and provides statistical information which can easily be saved to a file. By selecting maximum or minimum values from the results, the instrument can also automatically zoom into the selected waveform cycle for further analysis, potentially saving additional data analysis time.
Access to real-time measurement functions is a best-in-class ScopeCorder feature. Armed with a dedicated digital signal processor option, the ScopeCorder can perform mathematical calculations such as arithmetic operators with coefficients, integrals, and differentials, as well as higher-order equations on acquired measurement data.
The results of these calculations are displayed during waveform capture in real-time. In addition to mathematical operators, steep digital filters can also be selected to isolate or trigger on the amplitude of certain frequency components.
Trend up to 126 types of electrical power-related parameters in real-time, such as active power, power factor, integrated power, and harmonics, using a dedicated Digital Signal Processor (DSP). This enables the user to display raw waveform signals such as voltages and currents, along with power calculated parameters, and even the capability to trigger on all of them. Trend waveforms of each order of harmonics, bar-graphs, and vector displays can be displayed.
The following motor wiring systems are available on the ScopeCorder:
Taking advantage of the real-time calculations of power parameters allows engineers to create a high-channel count, time series data set of mixed signals including sensors, automotive serial bus data, and accessory analog and discrete inputs.
This is ideal for such scenarios as:
Today, engineers are increasingly incorporating measuring instruments into integrated test systems to automate measurement processes for time-efficient testing. For simplified interfacing and integration with an automated test system, the ScopeCorder is equipped with Ethernet, USB and GPIB interfaces. Moreover, software options allow the use of third-party software to control the ScopeCorder and transfer measurement results. A few examples are:
Visual C++/Visual Basic
TMTCL is a DLL (Dynamic Link Library) which enables engineers to easily develop Microsoft Visual C++ and Microsoft Visual Basic programs to communicate between the PC and the ScopeCorder.
For users of MATLAB, a dedicated MATLAB tool kit can be used to control instruments from within MATLAB or to transfer data from the instrument to MATLAB.
By utilizing the LabVIEW driver written for the instrument, a developer can dramatically reduce the amount of work required to enable a PC to control the instrument from within the LabVIEW environment.
No measurement is ever “correct.” There is always an unknown, finite, non-zero difference between a measured value and the corresponding “true” value. In other words, a user can never be 100% sure that an instrument is operating within its specified tolerance limits. Regular accredited calibration is a method for gaining quantifiable confidence in a measurement system by comparing the instrument’s performance to a standard of known accuracy. It is also advisable to calibrate not only the measuring instrument but also the extended measurement setup including sensors, cables, shunts, and other devices that are part of a test bench.
Without an ISO 17025 accredited power calibration, there is no guarantee that the measurements on an ISO 9001 certificate are correct. Depending on age and quality, a measurement instrument could drift out of specification due to temperature, humidity, oxidation, loading, or other reasons and may need to be “adjusted” to bring it back within specifications.
The guaranteed accuracy and precision of Yokogawa’s instruments in North America results from our ISO 17025 accredited calibration laboratory that is located in our Newnan, Georgia facility. Since we can process calibrations in less than ten business days, users benefit from fast turnaround and domestic shipping. Yokogawa also offers a “Gold Plan” including up to five years calibration and expedited service levels in a convenient, single purchase.
The Yokogawa DL950 ScopeCorder captures and analyzes a wide variety of electrical, physical sensor signals, and serial buses. It offers a unique combination of high sampling rates, for a detailed view and long recording times to monitor trends over time.