应用PROFIBUS-DP技术改造喂丝机控制系统

本文通过一个现场的应用改造的实例介绍了PROFIBUS-DP技术在喂丝机控制系统中的应用,简单介绍了使用PROFIBUS-DP通讯的组态和编程方法.     

SST-PFB-CLX在S7-200和Controllogix5000之间的组网通讯

通过EM 277 PROFIBUS-DP扩展从站模块,可将S7-200 CPU连接到PROFIBUS-DP网络。不同PLC之间通过通讯转换模块能够实现组网通讯和数据读写。SST-PFB-CLX实现了RSLOGIX5000在controlnet和PROFIBUS-DP之间的组网通讯。     

应用PROFIBUS-DP技术改造喂丝机控制系统

本文通过一个现场的应用改造的实例介绍了PROFIBUS-DP技术在喂丝机控制系统中的应用,简单介绍了使用PROFIBUS-DP通讯的组态和编程方法。     

AB-ControlLogix5000与SIMATIC S7-200PLC之间通讯数据处理方法

网络通讯是控制系统中不可缺少的一部分,数据通讯的实现不仅可以使我们实时监控现场设备的运行情况,还可以通过数据趋势、设备参数进行系统分析,确保设备安全稳定的运行。基于PROFIBUS-DP网络的AB-Control Logix5000与SIMATIC S7-200通讯在现场应用十分广泛,而两种控制器之间数据通讯的实现需要对数据类型进行转换,本文主要介绍了工业控制软件中常用的数据类型,并结合400万t选矿浮选控制系统(Control Logix5000)与鼓风机控制系统(S7-200)之间数据通讯的实现,详细介绍了REAL数转换为双INT数的实现过程。     

PROFIBUS-DP现场总线在热连轧控制系统中的应用

简述了德龙850 mm热连轧生产线自动化控制系统的配置,重点介绍了PROFIBUS-DP现场总线的应用,PROFIBUS-DP网中PLC主站与直流调速装置、变频器、S7-200、编码器等数据交换,各种厂家的产品在PROFIBUS-DP网做主站或从站的详细配置,PLC控制器对数据的读写。     

现场总线技术及其在轧机电气控制系统中的应用

本文介绍了PROFIBUS-DP现场总线的特点和基本功能。在我院为郑州中原铝厂设计的1450mm铝带箔冷轧机电气控制系统中，采用PROFIBUS-DP现场总线技术实现SIMATIC可编程序程控器与ABB全数字直流传动系统之间的通讯和控制，取得了良好效果。     

网络控制系统在感应加热设备中的应用

介绍了S7-300系列PLC与PROFIBUS-DP、以太网组成二级计算机网络控制系统在感应加热设备中的应用.     

流量计数据采集的网络化应用

通过对流量计接口数据的分析,设计出了流量计Modbus协议和PROFIBUS-DP现场总线协议之间转换的桥明了方案中Modbus协议转换为Profibus协议的具体特点及实施方法,解决了流量计只提供Modbus接口无法连到PROFIBUS-DP网络的问题。     

PLC与网络技术在氧枪传动控制中的应用

介绍转炉氧枪采用6RA70全数字传动,并应用PROFIBUS-DP网络技术,实现与PLC系统的数据传输和现场控制,提高了转炉控制的自动化水平.     

PROFIBUS-DP现场总线技术的网络优化

要:中铝山东第二氧化铝厂的控制系统采用PROFIBUS-DP现场总线通信协议,针对其东区过滤工艺段存在的通信故障问题,从PROFIBUS-DP网络拓扑结构、安装与布线规范、EMI屏蔽隔离等多个方面对PROFIBUS-DP网络进行了优化,优化后不仅解决了现有的通信故障,而且使网络通信质量得到整体提升,运行半年未发生网络故障报警。     

PROFIBUS DP总线在无缝400机组定径区的应用

本文介绍了使用西门子现场总线(PROFIBUS DP)技术完成中央控制单元与整流、变频单元间通信控制在生产现场的应用实例.S5-155U可编程序控制器通过IM308B模板将6RA24 SIMOREG K整流器和6SE70 SIMOVERT变频器联入PROFIBUS DP现场总线.中央处理器通过总线与传动装置进行数据交换,从而进行自动控制.PROFIBUS DP总线技术在定径区的使用,减少了现场电缆的敷设量,降低了事故率,设备的控制水平有了较大的提高.     

西门子S7-414-3DP在立推式加热炉控制系统中的应用

介绍了以S7-414-3DP西门子PLC为核心的立推式加热炉控制系统,详细描述了PLC的硬件组成及软件结构、通讯功能、操作界面及与上位机的通讯。     

基于SINEC—L2网的SIEMENS PLC与传动装置的通信方法

介绍了用ＳＩＮＥＣ－Ｌ２ＤＰ网络技术实现ＳＩＥＭＥＮＳＰＰＬＣ与调速传动装置的通信方法，以及相应的分布结构特点。     

鞍钢大型厂直流电机节能技术

介绍了一种基于SIEMENS 6RA70系列全数字直流调速装置控制系统。系统采用PROFIBUS DP通讯实现PLC与6RA70系列装置之间的数据传输,以PROFIBUS DP现场总线控制方式,自动检测生产过程中直流电机停止运行的大量而短暂的间歇期间,能够自动减少励磁电流。经测算,直流电机励磁电流自动减少50%,每天降低电能消耗5%以上。     

转炉辅助区域综合管控系统的开发

应用PLC自动控制技术,使用Wincc7.0和Step7作为编程开发工具,主站与从站采用Profibus DP通讯,采用Oracle10g数据库,开发了转炉辅助区域控制系统,主要包括基础自动化系统和综合管控信息系统。该系统在河北某钢厂应用后,运行安全稳定,实现各区域系统设备集中监控与远程操作,完善了设备硬件诊断及网络通讯诊断功能。     

DP980钢及DP980钢激光焊接接头的高周疲劳性能

摘要：为了研究DP980钢的高周疲劳性能,采用疲劳试验机对DP980钢和DP980钢激光焊接接头进行高周疲劳试验,得到Basquin方程,并利用光学金相显微镜和扫描电镜进行组织和断口分析。结果表明：DP980钢激光焊接接头的焊缝根部和顶部出现形状凹陷,焊接接头的质量为中等。DP980钢疲劳极限为341MPa,DP980钢激光焊接接头的疲劳极限为148MPa,激光焊接接头的疲劳极限较母材的疲劳极限降低约50%。对于DP980钢而言,铁素体/马氏体晶界是裂纹萌生的主要位置,疲劳断口为准解理断口。对于DP980钢激光焊接接头而言,疲劳裂纹源位于焊缝凹陷处,而非热影响区及母材,疲劳断口为解理断口。DP980钢和DP980钢激光焊接接头的疲劳裂纹扩展区均有明显的疲劳条带,并伴随有二次裂纹。     

High cycle fatigue behavior of DP980 steel and DP980 steel laser welded joints

For the study of the DP980 steel high cycle fatigue property, high fatigue tests of DP980 steel and DP980 steel laser welded joints were carried out with fatigue testing machine, the Basquin equation was concluded. Microstructures and fractures were analyzed by optical microscope and scanning electron microscope. The results show that DP980 steel laser welding joints have the weld concavity at the welding root and top, the quality of welded joints is medium. The fatigue limit of DP980 steel is 341MPa, the fatigue limit of DP980 steel laser welded joint is 148MPa, the fatigue limit decreases by 50% compared with the fatigue limit of the base metal. For DP980 steel, the crystal boundary of the ferrite/martensite is the main location of micro cracks initiation, the fatigue fracture of DP980 steel is the quasi cleavage fracture. For DP980 steel laser welding joints, the fatigue cracks initiation is located in the weld concavity, not in the heat affected zone, the fatigue fracture is cleavage fracture. DP980 steel and DP980 steel laser welding joints crack propagation is characterized by the obviously fatigue striations coupled with secondary cracks.     

Growth behavior of the 2 f1-f2 distortion product otoacoustic emission in tinnitus

High-resolution hearing threshold and 2 f1-f2 distortion product otoacoustic emission (DP) were measured with the same in-the-ear sound probe and same calibration at 51 frequencies between 500 and 8000 Hz in 39 sensorineural hearing loss ears associated with tinnitus. Using a primary tone setting L1 = 0.4L2 + 39 that accounts for the nonlinear interaction of the two primary tones at the DP generation site at f2, DPs were elicited in a wide range from L2 = 65 to 20 dB SPL. We failed to find a uniform DP behavior in the 39 tinnitus ears tested. Seventeen of them behaved like impaired ears without tinnitus. In these ears a linearized DP growth was observed where the DP level decreased and the slope of the DP I/O functions steepened with increasing hearing loss and as a result both the DP level and the DP slope strongly correlated with hearing threshold. The other population, 22 tinnitus ears, exhibited a poor or even inverse relationship between DP level and hearing threshold, i.e., displayed an increase of DP level with increasing hearing loss. Despite the severe hearing loss but due to the high level, DPs could be recorded well in the frequency range that corresponded to the appearance of the tinnitus. The DP slope, however, increased with increasing hearing loss and, therefore, did still correlate with hearing threshold revealing pathological alteration. The data suggest that the DP level alone is hardly capable of assessing hearing impairment in tinnitus ears and may even be misleading. Thus just the DP slope seems to be the only reliable indicator of cochlear malfunction around the tinnitus frequency. The observed nonuniform DP behavior suggests different cochlear impairments in tinnitus ears. In those ears where the DP level decreases and the slope of the I/O functions increases with hearing loss, cochlear sensitivity and tuning are supposed to be diminished. In those ears where the DP level increases with increasing hearing loss, a reinforced mechanical distortion is hypothetized to be generated by cochlear hyperactivity that can be the source of both the abnormally high DP level and the tinnitus.     

Strain Hardening Behavior of Dual-Phase Steels

A detailed qualitative and quantitative examination of the microstructure and mechanical properties of three different classes of DP600 and DP450 dual-phase (DP) steels was carried out. The tested DP steels are characterized by different alloying elements: aluminum, boron, and phosphorus. Among them, aluminum DP steels showed the lowest percentages of hard phases, while phosphorus DP steels exhibited the highest resistance values. The Hollomon, Pickering, Crussard–Jaoul (CJ), and Bergstrom models were used to reproduce the strain hardening behavior of DP steels. Relationships that correlate the fitting parameters with the chemical composition and the thermal cycle parameters were found, and the predictive abilities of different models were evaluated. The Pickering equation, among the tested models, is the best one in the reproduction of the experimental stress-strain data.     

Investigation on the Failure Mechanism of DP590-22MnB5 (Quenched) and DP590-DP590 Spot-Welding Joints

The failure mechanism of DP590-22MnB5(quenched) and DP590-DP590 spot-welding joints is studied through lap-shearing experiments,metallographic observation and three-dimensional finite element simulation.Both joints cracked on the DP590 steel,but the tensile shear strength of the DP590-22MnB5(quenched) joint is greater than that of the DP590-DP590 joint.A finite element model for the lap-shearing experiment is established according to the mechanical properties of DP590 and 22MnB5(quenched) steels and the metallographic analysis of welding spots.The simulation results show that the difference in the axis rotation of the two welding spots causes different distributions of stress and strain,which shifts shear loading condition to opening loading condition.Due to larger axis rotation angle of the DP590-DP590 joint,the stress concentration occurs at the middle of the nugget circumference,and it results in lower tensile shear strength of the DP590-DP590 joint.