Design And Implementation Of General Collection And Execution Unit Based On The Internet Of Things

With the development of IoT(Internet of Things), it has been integrated into applications in multi-industry and multi-field. Due to the diversity of sensors and the application environments, the methods of data acquisition in Sensor Networks varies, increasing the difficulty of development and the resources wasted in repetitive development. In this paper, a general IoT-based data acquisition and execution unit is presented. By integrating common types of sensors and signals, this unit completes the function of automatic identification and processing the collecting information from different signal input interface, which contributes to shortening the construction period of IoT industry and resource sharing.The system consists of five parts, which are control module, signal acquisition module, execution module, Internet access module and power supply module respectively. The control module uses a low-power ARM chip based on Cortex-M3 core architecture, its peripheral includes clock circuitry, reset circuitry, JTAG debug interface, BOOT start circuit, etc. The signal acquisition module is the composition of three major parts, including analog-signal circuitry, digital-signal circuitry and switch-signal circuitry. The analog-signal circuitry collects the voltage signal varies from 0 to 5 V and the current signal varies from 4 to 20 mA respectively. Digital-signal circuitry contains multiple interfaces such as single bus, pulse, CAN, RS232, RS485, IIC, SPI, ZIGBEE, etc, to acquire data from the corresponding sensors. The switching circuitry can only read the logic signal which is either logic high level or logic low level. The execution module is a combination of DAC output, PWM digital output and relay switch signal output, which generates the analog voltage signal, PWM signal and switching signal respectively. Internet access module is divided into Ethernet module and GPRS module, realizing the function of access internet. The Power supply module with DC power supply and lithium battery array provides power supply of the entire system.. System through acquire the configuration information from the server to complete initialization of collection ports, Rotationally scanning the corresponding ports and collecting the data of ports automatically, the system processes data and output control signal according to the corresponding trigger conditions of configuration information, and finally transmits corresponding data to the IoT server. Through the test under the circumstance of intelligent agriculture and industrial coal mine, expected result is achieved. The automatic recognition and processing of collected information from different input interfaces is also carried out, reducing the construction period of the IoT industry.The system played an essential role in Internet of things, it could accomplish the function of data of different signal types acquisition, processing and uploading, In the meantime, it is capable of receiving control information from the server to complete the function of control and execution unit. The test results show that this system is the generally applicable, implementation flexible and operative accessible, it avoids repetitive development and provides technical support to the rapidly building IoT system of industrial detection, monitoring and control.