Development Of A Universal Automatic Calibration And Test System For Intelligent Instruments

Intelligent instrument with functions of measurement,high measuring precision,fast response characteristics,widely used in field data collection of the distribution network.At this stage most of the factory test intelligent instrument in manual way,the process is tedious and prone to error,not suitable for mass production,also can not guarantee product quality.Aimed at the above problems,this paper researches and puts forward a universal automatic calibration and test system,which can automatically test all kinds of intelligent power meters,realize high-efficient and high-quality production,and can be configured according to different types of instruments.,testing requirements.The function of the test system designed in this paper includes two aspects: data calibration and function test,The functions of the test system include data calibration and function test.The function test includes analog precision test,digital input test and relay output test.The whole testing process is controlled by the background software system,and completed in strict accordance with sequential logic order,automatically generate test reports and store them in a specified directory for viewing.The system is composed of four parts: host,standard power source,intelligent I/O module and communication module,background host is responsible for editing and executing test tasks;the standard power source is used to output the standard three-phase current,voltage signal;intelligent I/O module is used to assemble the test circuit and analog switch signal,acquisition relay output signal;the communication module is a bridge between the background host and the intelligent I /O module,and sends the information collected by the intelligent I/O module to the background host.The system needs to complete the design of intelligent I/O module onhardware,Intelligent I/O module uses STMicroelectronics STM32F3 series chips as the microprocessor,including the power circuit,E2 PROM expansion circuit,RS-485 communication interface circuit,switch input circuit,the relay output circuit.Hardware driver choose Keil uVision4 as the development platform,the intelligent I/O module uses the Modbus communication protocol to communicate with the communication module.Software using multi-tasking mechanism for development on java platform.The key point of software development is the time difference of asynchronous communication.It consists of human-computer interaction module,data acquisition module,standard power source control module and data processing module.After the hardware design and software design is completed,the calibration and test of the intelligent instrument are carried out according to the test platform.The identification rate of the system is 100%,and the accuracy of the system simulation is achieved.