智能压力变送器的功能安全自诊断  

Functional safety self-diagnosis of intelligent pressure transmitter

作　　者：吕鹏勃 何志强 LV Pengbo;HE Zhiqiang(Chongqing Chuanyi Automation Co.,Ltd ChongQing 401121,China)

机构地区：[1]重庆川仪自动化股份有限公司,重庆401121

出　　处：《自动化与仪器仪表》2023年第4期301-304,共4页Automation & Instrumentation

摘　　要：在现代工业控制领域中,可编程电子硬件、软件系统的大量使用,大大提升了自动化程度。但由于设备设计中的缺失,以及开发制造中风险管理意识的不足,这些存在设计缺陷的产品大量流入安全控制系统中,已经造成了人身安全、财产损失和环境污染等灾难频出。为此,世界各国对石化过程安全控制系统、电厂安全控制系统、核电安全控制系统领域的产品安全性设计系统非常重视,并且将电子、电气及可编程电子安全控制系统相关的技术发展为一套成熟的产品安全设计技术,即“功能安全”技术。智能压力变送器由传感器、微处理器及模数/数模转换器组成。传感器用来采集被处理信号,采集端的失效诊断通过双A/D芯片采样冗余比较的方法来达到诊断目的;微处理器用来对数字信号进行综合运算和处理,微处理器的自诊断主要针对寄存器、程序指令、内存、时钟等各个资源模块的读写异常、功能失效、频率改变等问题进行自诊断设计;通过微处理器计算的压力信号最终通过数模转换D/A输出4 mA~20 mA模拟信号,模拟信号量的准确性与稳定性将直接影响整个变送器系统功能,通过A/D对模拟信号实时进行环路回采、比较,以确保电流输出正确与稳定,来实现自诊断的目的。功能安全自诊断实时检测压力变送器当前的运行状态,是否存在系统故障,是否存在模块功能失效,并实时将异常状态通过故障报警电流上报给安全控制系统,控制系统或者监控人员及时地作出安全响应以实现功能安全。In the field of modern industrial control,the extensive use of programmable electronic hardware and software systems has greatly enhanced the degree of automation.However,due to the lack of equipment design and the lack of risk management awareness in development and manufacturing,a large number of these defective products have been flowed into safety control system,which has caused frequent disasters such as personal safety,property losses and environmental pollution.For this reason,countries all over the world attach great importance to product safety design systems in the fields of petrochemical process safety control system,power plant safety control system and nuclear power safety control system,and develop the technology related to electronic,electrical and programmable electronic safety control system into a mature product safety design technology,namely“functional safety”technology.Intelligent pressure transmitter is composed of sensor,microprocessor and analog-to-digital converter.The sensor is used to collect the processed signal,and the failure diagnosis of the collection end is achieved by the method of double A/D chip sampling redundancy comparison;Self-diagnostics are designed for problems such as read and write exceptions,function failures,and frequency changes of each resource module such as registers,program instructions,memory,clock,etc.;the pressure signal calculated by the microprocessor is finally output 4-20mA analog through D/A The accuracy and stability of the signal and the analog signal will directly affect the function of the entire transmitter system.The analog signal is looped back and compared in real time through A/D to ensure that the current output is correct and stable,so as to achieve the purpose of self-diagnosis..Functional safety self-diagnosis detects the current operating status of the pressure transmitter in real time,whether there is a system fault,whether there is a module function failure,and reports the abnormal status to the safety control system in real time thro

关 键 词：功能安全 自诊断 智能压力变送器 微处理器 存储器 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]