| As a crucial link to offer protection to staff and environment in industrial production,the application of SIS become more extensive in industries such as petroleum,petrifaction,electric power and warehousing.At present,majority of the SIS are monopolized by overseas enterprises,some enterprises in our country are now actively and independently developing SIS with the TMR framework so as to break away from such monopoly.Automation testing system of SIS circuit board is a major measure to guarantee the function of system,performance and reliability and it has significant importance of improving productivity,quality and competitiveness.The paper designs overall testing process and detailed testing steps based on physical property and requirements of circuit board to be tested and put forward a general design scheme by combining overseas and domestic research status of automation testing system development,based on that and combine national and industrial standard,a series of requirements for subsequent hardware design have been put forward,these requirements cover structure,function of testing software and programming,conditions of usage,safety and EMC,reliability and testing indicators,serviceability and maintenance ability.Meanwhile,specific design requirements for test ability of the tested circuit board have been put forward too.Based on this,signal routing board and adapter board have been developed and Model selection and integration of testing devices,communication protocol of system and circuit board to be tested as well as design and implementation of software system,all of them have been completed,ultimately,debugging and testing has been performed on the circuit board to be tested.Hardware of automation testing system include IPC,process calibrator,signal generator,Hart modem,programmable power supply,electronic load,digital input/output card,analog input/output card,serial server,industrial camera,signal routing,adaptor card and self-check card and testing devices are general and easy accessible products of large market quantity.The software of automation testing system adopts Lab VIEW development platform and VISA technology,database of SQL and multithreading technology.The development of software follows the design philosophy of general utilization and modularity,which makes it possible to test each item automatically,meantime,it realizes the function of self-check,testing data storage and automatic testing report generation.EMS foundries officially put automation testing system in use and complete the function testing of circuit boards in all Safety Instrumented System,the application results show that automation testing system of SIS can conduct tests according to the scheduled testing flow path and steps and accurately identify failure of circuit board according to qualified criteria in function and in performance,it can conduct the work stably in a long term.Additionally,the testing system can not only conduct functional test in the production process,but also position the failure in the maintenance procedure. |
