A Feasibility Study of Real-Time, High-Speed, Multi-Channel Wireless Data Acquisition and Control System using MQTT Protocol

Abstract. Easy-to-use data acquisition methods are required for variable-rate irrigation (VRI) decision support systems. Plant canopy temperature is related to plant water stress. Plant height is useful as an indicator of plant health conditions and can be used to estimate yield potential. Therefore, measurements of plant canopy temperature and plant height coupled with spatial information in the field can be used for determining VRI water application depths. A center-pivot-mounted wireless data acquisition (WDAQ) system was developed to collect plant canopy temperature and plant height data in the field. Each WDAQ unit consisted of a GPS receiver, programmable data logger, infrared temperature sensor, ultrasonic distance sensor, solar power supply, and wireless data transmitter/receiver. The system included two WDAQ units installed on a four-span center-pivot VRI system. One unit was mounted at the middle of the third span, and the other was mounted at the middle of the fourth span from the pivot. The infrared temperature sensors were used to detect the canopy temperature, while the ultrasonic distance sensors were used to measure plant height. The WDAQ system was designed to continuously and simultaneously measure plant canopy temperature and plant height and record the spatial coordinates at each measurement location as the center pivot moved around the field. Data collected were wirelessly transferred to a receiver for data processing. This WDAQ system has been tested and evaluated in the field for two years. Test results indicated that the WDAQ system was able to record approximately 3,200 measurements from each sensor in one pivot circle (360°). The measurement error of the ultrasonic distance sensor was 0.2 to 3 cm in a measurement range of 14 to 209 cm, and the sensor-measured plant heights were strongly correlated with manually tape-measured plant heights in soybean and cotton crops (r2 = 0.97). Combined with the spatial information, measurements of plant height and crop canopy temperature were used to generate plant height and crop canopy temperature maps. Spatial variabilities of plant height and canopy temperature across the field could be identified from the maps and used in irrigation research. The WDAQ system has great potential for automatic creation of VRI prescription maps and plant-based irrigation scheduling. Keywords: Canopy temperature, Irrigation scheduling, Plant height, Sensors, Variable-rate irrigation.

Aiming at a multi-channel data acquisition and transmission system based on FPGA, the design scheme, functional circuit and logic design method of the system are introduced in detail. The system uses FPGA as the control core to control TLC2543 analog-to-digital converter and complete the circulation acquisition of 11-channel analog data. The transmission end uses Ethernet chip RTL8201 to communicate with the upper computer, which can monitor the data changes of each channel. The correctness of each function module is verified by software simulation. The design can meet the requirements of multi-channel signal acquisition and transmission.

Typically, multi-single-element photoacoustic computed tomography (PACT) systems utilize numerous ultrasound transducers arranged in cylindrical or hemispherical configurations for detection, combined with a single diffuse light source or multiple sparse light sources to illuminate the imaging target. While these systems produce high-quality 3D PA images, they require complex, multi-channel data acquisition (DAQ) systems to acquire data from all transducers. These DAQ systems are often bulky and expensive, significantly limiting the clinical translation of PACT systems for patient care. In this study, we evaluated the feasibility of using a compact and cost-effective Texas Instruments analog front-end DAQ module for multi-single-element PACT systems. By imaging a simple 3D phantom, we demonstrated the capability of this affordable DAQ board, with reconstructed images showing promise for practical and economical solutions in PACT systems. This advancement paves the way for broader applications of PACT in both research and clinical settings.

A computer-based data acquisition and analysis system was developed customized to EMG measurement and analysis requirements. The system was designed as an assistive tool for researchers studying human electrophysiology and kinesiology. A user-friendly interface characterized by a great adaptability and compatibility with other similar existing software packages was implemented, enabling multichannel acquisition, data storage and analysis. The application integrates the most frequent processing techniques required by EMG researchers and analysts, as well as a number of advanced signal processing techniques adjusted to the features of the EMG signal. The system comprises flexible signal analysis and display modules, forming a fully operational tool that can be easily configured to serve any similar purposed measurement requirements.

Lidar has emerged as an important technology for the high-precision three-dimensional remote sensing of the ocean. While oceanic lidar has been widely deployed on various platforms, its underwater deployment is relatively limited, despite its significance in deep-sea exploration and obstacle avoidance for underwater platforms. Underwater lidar systems must meet stringent requirements for high performance, miniaturization, and high integration. Single-photon lidar, by elevating the detection sensitivity to the single-photon level, enables high-performance detection under the condition of a low-pulse-energy laser and a small-aperture telescope, making it a stronger candidate for underwater lidar applications. However, this imposes demanding requirements for the data acquisition system utilized in single-photon lidar systems. In this work, a self-developed multi-channel acquisition system (MCAS) with a high-resolution and real-time histogram statistics capability was developed. By utilizing field-programmable gate array (FPGA) technology, a method that combines coarse counters with multi-phase clock interpolation achieved an impressive resolution of 0.5 ns and enabled a time of flight duration of 1.5 μs. To address counting instability, a dual-counter structure was adopted in the coarse counter, and real-time histogram statistics were achieved in the data acquisition system through a state machine. Furthermore, the non-uniform phase shift of the clock was analyzed, and a correction algorithm based on code density statistics was proposed to mitigate the periodic modulation of the backscattered signal, with the effectiveness of the algorithm demonstrated through experimental results. The robustness and stability of the MCAS were validated through an underwater experiment. Ultimately, the development of this compact acquisition system enables the implementation of underwater single-photon lidar systems, which will play a crucial role in underwater target imaging, obstacle avoidance in underwater platforms, and deep-sea marine environment monitoring.

Digital phased array antennas (DPAAs) have been widely used in modern radar systems. The flexible production and testing of large-scale DPAAs are becoming a hot research topic. The dedicated calibration elements are passive because they do not have transmitter and receiver modules. These elements cannot be used to test DPAAs. In this paper, we design a multichannel automatic test and data acquisition system for DPAAs. Our motivation is to use the system to verify the correctness and stability of an entire DPAA. The system can achieve snapshot data acquisition of 1152 optical fibers, and it can also process echo data in real time by digital beam forming (DBF) and record the processing results. At present, the system has been put into production for testing of large-scale DPAAs, and it can test the DPAA flexibly and steadily.

In order to meet the tomato color sorting system with the requirements of multi-channel data acquisition and real-time processing, [ ]firstly, a multi-channel color digital acquisition and processing technique program based on FPGA were proposed . Then, a multi-channel data acquisition and real-time parallel processing system was built. The RGB color sensors were slected as detection components and the FPGA chip EP1C3T144C8 was slected as a core of data acquisition and processing. Meanwhile, ports of signal acquisition and the solenoid valve control were adopted a two-way analog switch HC4051 for saving I/O ports of FPGA. Thirdly, under the modular design and module reuse principles, we developed all modules with VHDL Language in QuartusII development environment. Finally, RTL and time sequence simulation for the system were done. The results showed that the connections between the modules accord with control logics. [²»´o¶O accorded ¹ýE¥E½] The performance of system time sequencev are good, which can meet with the requirements of real-time processing of tomato color sorting. On these bases, we also conducted a tomato sorting test verification. The results showed that the average accuracy of sorting is 98.70% and coefficient of variation is 0.01. This results can meet requirements of production.

Municipality upgrades to wireless SCADA system for future growth

Smart grid is the most ingenious and experimental technology in the present era. Assimilation of information and communication technologies with electrical infrastructure is the fundamental part of smart grid deployment. Smart grid communication architecture is a methodical framework of networks incorporating varied set of communication standards. Microgrid is the significant component of smart grid as it facilitates and expedites the usage of renewable energy assets. It can resolve the critical problems like unelectrified villages, electricity theft, depletion of fossil fuels, GHG emissions and greenhouse effect. Smart microgrid can function in two modes, namely grid-connected and island mode. It also encompasses hierarchical communication networks for automation of entire system. This paper describes the design and implementation of data acquisition and control system for smart microgrid prototype using IEEE 802.3 and IEEE 802.11 standards.

There is a strong trend towards wireless networked Real-Time Control Systems. However, a variety of factors such as the variability of wireless channel capacities, multi-path fading, and ambient interference make it extraordinarily difficult to design and implement Wireless Control Systems (WCSs). To attack the uncertainty in available communication resource in WCSs, this chapter presents an Adaptive Feedback Scheduling scheme that takes advantage of the methodology of cross-layer design. The proposed approach exchanges information across the physical layer and the application layer in the presence of noise interference and link transmission rate variations. The overall QoC is guaranteed through controlling the deadline miss ratio of control loops. Design parameters of the feedback scheduler are adapted to dynamic changes in wireless channel capacity. To further improve the feedback scheduling performance, an event-driven invocation mechanism for feedback schedulers is suggested. Simulation results demonstrate that this approach is efficient to deal with channel capacity variations and noise interference, thus providing an enabling technology for wireless control in dynamic environments. It is also argued that in this context event-driven invocation mechanism improves the performance of the feedback scheduling system.KeywordsSampling PeriodTransmission RateMedium Access ControlControl PerformanceMedium Access Control ProtocolThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The low-power wireless data acquisition and transmission system based on ZigBee is designed.The main work include the following aspects: 1)The circuit design and the software design of the system. 2)The multi-channel sensor data acquisition interface and the software of the system design. 3)Low-power design method for the node software. 4)The system based on ZigBee is build and debugged. The results show that the system has some advantages with lower data error rate. It is able to meet the needs of remote monitoring of the parameters on industrial environment.

This paper describes a high-speed data acquisition and transmission system for millimeter-wave imaging based on optical fibre and PCIe interfaces, which includes a multi-channel analog-to-digital conversion module, a data transmission module, and a data reception module. The scheme can circumvent the inherent shortcomings of bulky volume, poor reliability, and inability of large-scale expansion of array channels caused by the multi-channel data transmission system using multi-strand SMA cables, and has the advantages of small volume, light weight, fast data transmission rate, and easy to upgrade the performance, etc. It can be widely applied to the multi-channel data acquisition and transmission system, and has a broad application prospect in the field of array imaging radar and sonar imaging.

The paper designed a multi-channel data acquisition system based on PXI 6281. It used DAQmx technology in LabVIEW for synchronous analog channel data acquisition. It realized multi-channel real-time data acquisition, processing, display and data auto-saving. Data acquisition system consists of three major modules: the pressure measurement module, the motor speed measurement modules and real-time temperature measurement module. It has advantage of short cycle of technological upgrading, development and low maintenance costs. It has some reference value for other data acquisitions.

The performance degradation due to environmental factors represents a major shortcoming to the solar PV system making them untrustworthy for dessert or remote plants. Real-Time monitoring systems are extensively required in the remote PV system for gathering all parameters for estimating system performance and optimization purposes. Many existing studies present wired data acquisition systems, using LABVIEW license software, which are costly and not easily accessible. The wired data acquisition systems are accessible only near the PV systems. There are some wireless data acquisition systems, but they depend on license-based software and cloud services. There are very few wireless data acquisition systems using open-access software, which are monitored and recorded fewer parameters at a very high cost. The existing data acquisition systems are either continuously connected to supply or manually controlled, require the manpower to operate the system near the remote PV plant. These issues can be eliminated by using the proposed internet of things (IoT) based data acquisition system (DAQ). The proposed data acquisition system is based on open-access software and cloud service. In this paper, we presented all the design steps of the proposed low-cost data acquisition system systematically, also tested the performance of the proposed IoT enabled data acquisition system (DAQ) under harsh environment conditions over 28 days. Real-time test results revealed that the suggested data acquisition system is appropriate, reliable, cost-effective, and suitable for harsh outdoor conditions for monitoring and gathering operational information of the PV system to assess its performance. The information updated by the proposed DAQ system can be seen from anyplace. The proposed data acquisition system can be controlled (ON/OFF) by using the Wi-Fi-enabled switch according to the requirement. In this way, we can not only save energy by 58% but also save the life of sensors. It has been observed that the output power of the PV module is reduced by 13% within 28 days without adopting any cleaning technique. In this paper, we also discussed the comparison between the proposed and some exiting methodology of the data acquisition systems.

This paper deals with the analysis of multi-channel data-acquisition systems with the aim of identifying and combining the main uncertainty contributions. The approach based on the GUM uncertainty framework has been implemented to characterize and combine the different contributions. Particular attention has been paid towards cross-talk effects, which can be not negligible above all in multiplexed data-acquisition systems. The uncertainty analysis is described for a commercial data acquisition board, whose cross-talk specification is not suitable for a reliable uncertainty estimation in operating conditions. For this reason, an experimental characterization of the board has been performed and the obtained results are provided. These results highlight that a proper characterization of a data-acquisition system is effective in estimating the actual performance at the operating frequency and provide valuable information in terms of source resistance and input-channel configuration that make cross-talk effects negligible.