Leveraging the Best Ideas
Just as it’s always done, the data acquisition world is adapting the latest and greatest technologies from the general embedded computing industry. Virtualization, AI and IoT are all part of the mix.
The data acquisition industry boasts a long history of embracing and adapting technologies, interfaces and board form factor technologies from the embedded technology world. Over the last several years, that’s meant moving to USB, PCI Express and web-based interfacing. Now that shift is firmly behind us. And the next wave of data acquisition appears to be looking toward advanced embedded ideas such as virtualization, self-automation and Artificial intelligence (AI).
Meanwhile, the data acquisition world is moving toward embracing popular software and open-source solutions such as Python and Arduino. Over the past 12 months, these vendors have rolled out a host of new products designed to meet the diverse and sophisticated needs of today’s data acquisition system developers.
PLATFORM-INDEPENDENT SOLUTION
The idea of de-coupling the software from the hardware is a growing trend in the embedded systems world, and the trend seems to be moving into the data acquisition space as well. Along just those lines, in June Delphin Technology launched its ProfiSignal 20 package, a solution for platform-independent measurement data analysis and process control.
Measurement data analyses and process visualizations created with ProfiSignal 20 can be accessed via smartphone, tablet, laptop and PC, optimally presented according to the operating setup (Figure 1). The “Go” version of the new ProfiSignal 20 measurement technology software is used for fast visualization, monitoring, analysis and archiving of measurement data. In addition to versatile, configurable and, when required, multi-axis y(t) diagrams, new multi-track diagrams are now also available. Measurement data from multiple channels can be displayed synchronously for instant comparison. y(x) diagrams for analyzing correlations between different measured variables are also available.
ProfiSignal 20 uses hardware-related calculation routines to enable lightning-fast switching between live and historical measurement data as well as ultra-smooth zoom functions. ProfiSignal 20 Go’s range of features are rounded off by powerful statistical functions for data analysis, a recorder function for carrying out series tests and measurement data export to various file formats.
The ProfiSignal 20 “Basic” version enables users to create individualized diagrams for visualization and process control. A wide range of control and monitoring elements are provided, which can be combined to create user-defined dashboards. An object designer greatly simplifies the creation of complex projects as well as multiple projects with similar visualizations. All functions in ProfiSignal 20 Go, with its range of diagram types and analysis and export functions, are also fully included in ProfiSignal 20 Basic. A further ProfiSignal 20 feature is its innovative SCACH function. Simply scanning QR codes via a smartphone or tablet gives access via the mobile device’s display to selected machine data as well as full system visualizations. Measurement data analysis and process control have never been easier.
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AUTO AUTOCALIBRATION
For its part, Diamond Systems offers an array of data acquisition features on some of its SBCs and I/O boards. Among these features is an autocalibration capability. In October, the company released a white paper explaining the benefits of autocalibration, as well as advanced version of called automatic autocalibration or auto autocalibration [1].
Diamond’s first board to offer auto autocalibration is its DMM-32DX-AT, an advanced embedded A/D I/O board. The board’s patented auto autocalibration technology is circuitry that enables the automatic calibration of the board in response to changes in temperature without requiring any involvement by the user or application program (Figure 2). An on-board microcontroller monitors the board’s temperature and uses on-board calibration circuitry to bring the board into calibration whenever needed, totally automatically. Typical accuracy post-calibration is ±1LSB. The calibration threshold is set for 5°C, which typically limits measurement errors to only ±2 to ±3LSB pre-calibration.
DMM-32DX-AT’s 32 A/D input channels feature high-accuracy 16-bit resolution, 250kHz maximum sampling rate, programmable input ranges and user-selectable single-ended/ differential configuration. Its four D/A output channels feature user-selectable output ranges as well as a programmable waveform generator feature. Those channels are 16-bit standard, 12-bit optional. The 24 digital I/O feature bit by bit direction programmability as well as buffers for enhanced output current of -15mA (logic 1) / 64mA (logic 0). On-board programmable counter/timer circuitry includes a 32-bit counter/timer for A/D and D/A sample timing, as well as a 16-bit counter/timer for general counting, timing, and programmable interrupt functions.
Extended temperature operation of -40°C to +85°C is tested and guaranteed. Diamond’s advanced Universal Driver software is included free with DMM-32DX-AT and all its SBC and I/O boards. The Universal Driver provides a programming library that simplifies control of all the board’s features and enables system developers to develop application software quickly. The board uses only ceramic capacitors for durability in high altitudes and other harsh environments.
PYTHON LANGUAGE SUPPORT
Python is a powerful object-oriented programming language. You often see it used by authors of many project articles in Circuit Cellar. In September, Measurement Computing Corp. (MCC) announced the release of Python support for MCC DAQ devices. Python is now supported under the open-source MCC Universal Library Python API. Python Support for MCC DAQ is compatible with most MCC USB and Ethernet DAQ devices (Figure 3).
Python provides the flexibility to extend and expand DAQ applications quickly and easily by eliminating many of the code maintenance tasks required in other languages. It focuses on code readability, and a shallow learning curve, saving time that might have otherwise been spent fighting with language details. Python Support for MCC DAQ is open-source, with the source code available on Github: https://github.com/mccdaq [2].
Many MCC products—including most USB, Ethernet and Bluetooth hardware—are now supported under the open-source MCC Universal Library Python API for Windows. Linux support is available as part of the MCC Universal Library for Linux package. The mcculw package contains an API for interacting with Universal Library in Windows. And the uldaq package contains an API for interacting with Universal Library for Linux. Both packages are implemented in Python as a wrapper around the Universal Library C API using the ctypes Python Library. Both were developed and are supported by MCC.
MODULE SUPPORTS ARDUINO
As mentioned earlier, the data acquisition industry has a history of adopting any and all technologies from the embedded computing industry that provide benefits that suit its needs. Arduino can now be counted among those technologies. In September, the distributer CAS Dataloggers announced a the DigiRail NXprog I/O module from Novus Automation.
The NXprog unites the best of both worlds: the reliability and robustness of an industrial device for automation applications with the ease of programming from the Arduino community (Figure 4). It provides a rich mix of integrated analog and digital I/O signals, allowing DigiRail NXprog to be used as an extension of standard data logging, data acquisition and automation systems, or as a brain for customized applications.
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Compatible with Arduino, DigiRail NXprog allows the use of high-level programming languages, such as C/C++, which allow the implementation of complex algorithms such as state machines, logic, mathematical functions, statistical analysis and controllers. When compared with traditional ladder logic or IEC standard programming found in most PLCs, the NXprog provides a modern programming environment along with access to an extensive community library of example code.
The DigiRail NXprog offers a complete set of I/O capabilities including two Universal Analog Inputs thermocouple, PT100/1000 RTD and NTC. It also provides analog outputs, digital/counter inputs, digital and relay outputs, USB, RS485 and Ethernet. The NXprog utilizes an ATMEGA4809 processor with 48KB of flash memory and 256KB of EEPROM along with a battery-backed real-time clock, watchdog timer, and brown-out detector.
To enable communication with other devices, the NXprog relies on the industry-standard Modbus communications protocol. It supports the Modbus RTU protocol via the RS-485 interface and Modbus TCP via the Ethernet interface. When used as a Modbus slave, it offers two sets of registers: one to directly access the I/O channels and one set of registers shared with the Arduino environment.
MACHINE CONDITION MONITORING
One particular flavor of data acquisition that’s seeing a lot of activity these days is machine condition monitoring (MCM). By monitoring the vibrations and other physical conditions of machinery, factories can address maintenance issues before they occur. Feeding such needs, in March ADLINK Technology released its MCM-204 edge data acquisition system for MCM. Powered by the Arm Cortex-A9 processor, the MCM-204 is designed as a standalone data acquisition system device without the need for a host computer, and provides dual Ethernet ports to transmit data back to the backend server and enable daisy-chain connection of multiple devices (Figure 5). Commonly used vibration-related indices, such as voltage, FFT and RMS, can be calculated by the MCM-204, bringing the benefits of edge computing to a large-scale infrastructure.
In addition, the MCM-204 offers flexible support for various data access options, providing worry-free remote management and firmware/algorithm update through the built-in web console. All these features make the MCM-204 well suited for remote real-time monitoring, analysis and control. ADLINK’s ultra-compact MCM-204 features a 24-bit high resolution ADC and captures high-frequency signals at 128KSPS.
All channels have a built-in IEPE 4mA excitation current source, eliminating the need for additional signal conditioning to trigger sensors to capture signals. In addition, the MCM-204 can also support digital tachometer, digital temperature sensor and voltage output load current sensor functions for acquiring rotating speed, temperature and load current of the machine, thus providing a wide range of options for equipment monitoring tasks. Furthermore, this all-in-one solution has rich built-in data type support, including voltage, FFT data and RMS_OA. Users can easily build a complete and powerful real-time monitoring system without having to expend effort on programming development.
To enable a decentralized structure, the ADLINK MCM-204 offers an exclusive Custom Filtering Algorithm import mechanism that allows users to modify filter or pre-processing algorithms in C/C++ and compile under Linux. The MCM-204 provides the ability to migrate domain-know-how filtering algorithms to the edge in a secure manner.
VIBRATION SENSING GATEWAY
AI is now firmly entrenched in the embedded world and recently the data acquisition industry is leveraging AI as well. According to Advantech, AI is a powerful technology and many businesses want to adopt predictive maintenance (PdM) or prognostic and health management (PHM) solutions to make sensible proactive maintenance decisions in order to increase performance benefits and prevent downtimes. The problem is that, due to technical feasibility and economic factors, many owners or operators of valuable assets like CNC machines in factories and other critical assets are hesitating implementing such systems.
To address this, in October Advantech released an embedded application-ready solution—the WISE-750 intelligent vibration sensing gateway, which is developed to provide a simple way to realize low cost predictive maintenance. This all-in-one solution includes from high-accuracy accelerometer for sensing and collecting vibration signal, and WISE-750 intelligent machine-learning vibration gateway for edge computing and data acquisition to the integrated AI Utility for users to easily build machine learning models without experts (Figure 6). This solution greatly reduces the complexity and the cost of AI implementation.
Implementing and maintaining a predictive maintenance solution can be expensive and difficult because it requires specialized domain expertise across sensors, data acquisition, IoT platforms, data science and more. Advantech’s WISE-750 not only serves as the data acquisition hardware itself, but also as a pipeline from model training to inference. The WISE-750 AI utility provides an all-in-one solution so that users can configure the data acquisition, test the WISE-750 device, train and download the machine learning model in one program.
WISE-750 features a Renesas RZ/T1 MCU and e-AI technology so that machine learning could be run on MCU level devices. The RZ/T1 realizes real-time control of industrial equipment and networking via a single chip. It has an Arm Cortex-R4 Processor with FPU (floating processing unit) core, which is designed for real-time processing at 600MHz. The Renesas RZ/T1 MCU and e-AI technology can parse higher-level descriptive machine learning code such as Python to code executable by lower level machine code, C/C++, and even binary code. e-AI technology optimizes processing in the MCU, so that the machine learning algorithm can be executed with lower resources consumed.
MULTIFUNCTION I/O MODULE
The magic of semiconductor integration has enabled board vendors to combine multiple functions onto a single board, where in the past multiple boards were required. This trend has emerged in the data acquisition board market as well. In an example along those lines, in September Gantner Instruments released its Q.series X A192 I/O module. The A192 has been designed with critical aerospace testing applications in mind—for instance static fire test of rocket engines, structural health monitoring, fatigue validation and iron bird testing (Figure 7).
The module’s universal analog input can be configured for either voltage, current, resistance, RTD, thermocouple, strain gage or IEPE measurement. To allow for greatest flexibility in selecting the appropriate sensors for your test bench, the A192 provides fully programmable transducer excitation in combination with an adjustable input range and amplifier gain (automatic).
Like any of the Q.series X modules, various communication buses are supported; Ethernet, EtherCAT and LocalBus. In addition, the A192 includes an analog output to share the measurement signal with, for example, a control command system or redundant data logger. The two onboard digital I/O channels are freely configurable and can be used to communicate status to the test bench emergency system. TEDS can be added to simplify system setup, self-check or for sensor traceability. And, not least of all, the module comes with three-way galvanic isolation up to 500VDC.
10-BIT PXI DIGITIZER
Adapted from the PCI bus decades ago, the PXI form factor remains a staple in the data acquisition industry. Later, PCI Express was adapted as PXI Express. The latest PXI Express offering from Teledyne SP Devices is its ADQ8-4X board—a 10-bit digitizer with software-configurable sampling on two or four channels (Figure 8). The supported sampling rate is 4GSPS in 2-channel mode, and 2GSPS in 4-channel mode. This complements the previously released ADQ8-8C (8 channels, 1GSPS) by offering faster sampling at two different rates.
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ADQ8-4X is available in PXI Express form factor and therefore supports a mix-and-match approach where different digitizer models are used in the same system. The wide selection of models with different resolution, sampling rate and channel count enables system developers to implement cost-and performance-optimized multi-channel systems. Large systems with many channels can be distributed over many chassis with a timing alignment better than 200ps. Also, due to the modular architecture, the systems can be extended gradually over time.
Custom real-time digital signal processing (DSP) can be integrated on the onboard Xilinx FPGA through an optional firmware development kit, and a software development kit (SDK) is included free of charge. The board’s flexible analog front-end (AFE) has 1GHz analog input bandwidth, programmable DC-offset and variable input voltage range. High-precision multi-unit synchronization is provided for large installations. 
RESOURCES
References:[1] http://www.diamondsystems.com/files/binaries/Autocalibration%20White%20Paper.pdf
[2] https://github.com/mccdaq
ADLINK Technology | www.adlinktech.com
Advantech | www.advantech.com
CAS Dataloggers | www.dataloggerinc.com
Delphin Technology | www.delphin.com
Diamond Systems | www.diamondsystems.com
Gantner-Instruments | www.gantner-instruments.com
Measurement Computing | www.mccdaq.com
Novus Automation | www.novusautomation.com
Teledyne SP Devices | www.spdevices.com
PUBLISHED IN CIRCUIT CELLAR MAGAZINE • JANUARY 2021 #366 – Get a PDF of the issue
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Jeff served as Editor-in-Chief for both LinuxGizmos.com and its sister publication, Circuit Cellar magazine 6/2017—3/2022. In nearly three decades of covering the embedded electronics and computing industry, Jeff has also held senior editorial positions at EE Times, Computer Design, Electronic Design, Embedded Systems Development, and COTS Journal. His knowledge spans a broad range of electronics and computing topics, including CPUs, MCUs, memory, storage, graphics, power supplies, software development, and real-time OSes.
