西门子S7-1200的设计与应用 第5讲 食品生产线喷嘴控制的S7-1200设计

PWM是一种周期固定、脉冲宽度可以调节的脉冲输出,是数字量输出。在S7-1200 PLC中,它提供两个输出通道用于高速脉冲输出,分别可以组态为PTO或PWM,本案例则充分利用了PWM功能来实现了食品生产线的喷嘴控制,取得了良好的效果。     

西门子S7-1200PLC定时器的典型应用

介绍西门子新一代S7-1200 PLC定时器的典型应用.     

西门子S7-1200实现水泥行业重大突破

2009年9月1日，西门子自动化系统部S7-1200产品成功获得河北唐山某电器订单。实现S7-1200在北方水泥包装行业的重大突破。 西门子S7-1200具有高效、便捷的通信效果。可以实现八个水泥包装控制器的联动效果。在西门子自动化系统部的支持下，西门子北方区PLC产品推广经理对S7-1200产品进行精彩地演示、推广宣传．     

西门子S7-1200的设计与应用 第7讲 通过S7-1200与触摸屏控制工作台滑动座

运动控制被广泛应用在包装、印刷、纺织和装配工业中。S7-1200独有轴工艺对象,通过硬件组态、面板调试和诊断功能即可实现在线手动控制,最后通过调用相关指令实现自动控制。本案例介绍了通过S7-1200与触摸屏来实现工作台滑动座电机的运动控制。     

基于步进电机驱动自动生产线输送系统的PLC控制

步进电机是一种专门用于速度和位置精确控制的特种电机,满足自动生产线中输送单元的精确定位功能。利用西门子S7-200PLC内置PTO/PWM发生器可以方便为步进电机驱动器提供脉冲,通过S7-200的运动包络配置功能,可以实现步进电机不同运行模式的控制。     

S7-1200与变频器的USS协议通信

介绍了S7-1200与变频器MM440通信的硬件接线,变频器的参数设置和PLC的程序设计方法,给出了通信实验的结果.     

西门子S7-1200的设计与应用 第9讲 S7-1200与IFIX在变频器监控中的应用

OPC是随过程控制的发展产生的一种工业标准,它既可以用于将现场PLC设备的数据采集到DCS或SCADA中来,也可以用于将数据从一种DCS或SCADA系统采集到另一种DCS系统、SCADA系统或其他上位应用程序中。S7-1200作为优秀的下位机PLC,它可以通过OPC技术与IFIX等优秀组态软件进行数据通信。本案例主要介绍了S7-1200与IFIX在变频器监控中的应用。     

西门子S7-1200的设计与应用第1讲自动分拣装置的PLC控制

在以S7-1200为核心的控制系统中,输入/输出部分用以接收信号或输出信号,便于与PLC进行人机对话.输入的有条码读入器,输入模拟量的电位器等;输出的则有打印机、编程器等.随着技术进步,这种设备将更加丰富.通过自动分拣装置的实现,可以进一步将S7-1200应用到以前使用S7-200的任何场合中去.     

Minas A4系列交流伺服电机的PLC控制

本文采用西门子S7-224为主机,实现了时Minas A4系列交流伺服电机的控制,通过PTO发出频率可变的高速脉冲控制电机运行,利用高速计数器对电机的编码反馈信号进行计数,实现了闭环控制,可在机械加工、生产线等系统中与其它设备实现无缝连接,提高整体的自动化水平.     

基于PROFINET IO的S7-1200控制器与G120变频器通讯

针对PLC与变频器之间通讯时电机速度精细调节难的问题,应用新一代高速工业以太网PROFINET通信技术,将S7-1200PLC、G120变频器和触摸屏构成一个小型局域网.采用CSM1277作为小型交换机,三者之间采用以太网通信,建立通过PROFINET总线实现西门子S7-1200PLC与G120变频器通讯的方法.在分析...     

Does the Patent Office respect the software community?

The US Patent and Trademark Office (PTO) is now issuing about 20,000 new software patents every year-a tenfold increase in the last six years. Considering these inexplicable numbers, the IEEE, the ACM, and similar organizations should ask the PTO on what basis it thinks there are 20,000 novel and not obvious software inventions each year. The Japanese and European patent offices are demonstrating the same problems, but there are a few well-known reasons why the PTO issues so many patents: the indifference to prior art, the flood of patent applications, and the patent examiners' assembly-line working conditions     

Adaptive predefined-time observer design for generalized strict-feedback second-order systems under perturbations

This article studies the predefined-time observation problem of generalized strict-feedback second-order systems commonly encountered in practice. A nonaffine control input, a matched perturbation, and nonlinear functions satisfying the Hölder growth condition are considered. A class of adaptive predefined-time observers (PTOs) is designed to reconstruct unknown states and lumped perturbations based on a barrier function and specific time-varying functions. Distinct from existing observers for strict-feedback systems, the PTO accomplishes a complete reconstruction in a predefined time with trivial peaking observation errors. Furthermore, the upper bound of the settling time of the PTO is tightly and explicitly predefined by only one design parameter, and is irrelevant to the initial conditions. Hence, tuning procedures for the physically realizable temporal demands become less conservative and more straightforward. Moreover, the adaptive coefficients of the PTO are self-adjusted along with the magnitude of perturbation, efficiently improving the transient performance under wide-range perturbations. Finally, numerical simulations on a robot manipulator system demonstrate the effectiveness of the PTO.     

Intellectual property protection for multimedia application. 2.Putting the pieces together

In its recently published guidelines (60 Fed. Reg. 28778, June 2, 1995), the US Patent and Trademark Office (PTO) said computer software programs stored in a tangible medium, such as a floppy disk, are patentable and must be examined to determine whether the substance of a computer-program related invention is a significant advance over prior technical achievement justifying the grant of a patent. In the past, the PTO had simply refused to examine the substance of such an invention. The PTO attributed its new approach to recent decisions by the Federal Circuit Court of Appeals, which decides all patent appeals, favoring the patenting of software-related inventions. The paper discusses the items affected and considers multimedia applications     

The PTO on software patents

The Patent and Trademark Office (PTO) has been fighting patents on algorithms and other computer software for the last 30 years, but it has now decided to throw in the towel. According to draft software patent guidelines just released for public comment, the PTO is now willing to grant a patent on a computer program procedure as long as the patent is limited to a procedure if encoded into a machine-readable floppy disk, DRAM chip, and other storage medium or memory. Members of the public may file comments in writing or by Internet until July 31, but perhaps the PTO will extend the rather short comment period     

Effects of PbTiO3 seeding layer on electrical properties of PbZr0.4Ti0.6O3 thin films

Improvements in the ferroelectric properties were obtained by controlling process parameters of the lead titanate (PTO) seed layer. Highly oriented (1 1 1) perovskite lead zirconate titanate (PZT) films yielded the largest polarization switching charges, with an improved retention behavior, compared to those of PZT films without a PbTiO₃ seed layer. The degree of (1 1 1) orientation in a PZT perovskite film increased, when an additional heat treatment process was not applied during formation of the PTO seed layer. In addition, PTO seed layers showed the best results when 8% excess Pb was supplied.     

TINA and the Software Infrastructure of the Telecom Network of the Future

The overall goal of the TelecommunicationsInformation Networking Architecture (TINA) is to defineand specify a software architecture for thetelecommunications infrastructure which encompassesnetworking, network services, and operations, to handle theincreasingly distributed nature of software in networks.The purpose of this paper is to describe how TINA may bepositioned in the software infrastructure of future telecommunications networks, with thefocus on the infrastructures of Public TelecommunicationOperators (PTOs). An architecture for a new PTO networkinfrastructure is proposed and the needs that this architecture satisfies are discussed.The concept of the programmable network isintroduced to satisfy the PTO need to quickly trial anddeploy new services. Five aspects of this targetarchitecture are discussed, namely: a client/serverarchitecture, a service creation architecture, anapplication architecture, a PTO federation architecture,and a new management architecture. The potential role of TINA in each aspect is described, and thepotential benefits of TINA to PTOs aresummarized.     

Patenting signals

The US Patent and Trademark Office (PTO) has decided to encourage inventors to file for a new kind of patent that you surely would never have dreamed possible before. The PTO proposes patents on signals. Say you think up a new algorithm for signal compression or even a new algorithm for sorting-call it Blister Sort. It has been accepted for some time that you could get a method patent covering a method of compressing signals in accordance with your algorithm. By the same token, you could get a patent for a method of sorting data in accordance with the Blister Sort algorithm. That is, if the algorithmic procedure is novel and unobvious. More recently, the PTO decided it should allow patents on floppy disks and other storage media or devices (ROMs, for example) encoded with computer-readable program data. Thus, you can now get a patent on a floppy disk containing computer program code for carrying out Blister Sort. The PTO's latest idea is to spread the idea of floppy-disk patents beyond tangible storage media and devices to “propagated signals”. This would mean issuing a patent claim to “a propagated signal carrying computer-readable information representing a computer program to carry out a Blister Sort on computer-readable encoded information (data)”     

Proximate time-optimal control of third-order servomechanisms

The problem of proximate time-optimal control of third-order systems is considered. Two proximate time-optimal servomechanisms, PTO53 and PTO53τ, are proposed for type-3 and type-2 third-order plants, respectively. Theorems stating sufficient conditions on each system's control design parameters to ensure global stability are given, and it is shown that the control parameters can be adjusted to accommodate, more or less, disturbances and unmodeled dynamics in the system. The approach used to develop the controllers is that of constructing a `slab' in three-dimensional state space that describe the `switching' structure of the control. The technique relies on three-dimensional phase-space analysis, which is rarely applied to systems of order three or higher. Simulation and experimental results demonstrate the performance of the algorithms developed     

Anti-knockoff article protection law

IEEE-USA, the IEEE's US Activities Board, has proposed to Congress that it enact a new form of “anti-knockoff” intellectual property protection for “fast-moving technology”. The new form of intellectual property, which IEEE-USA calls “article protection”, would be a form of petty patent. Inventors and companies would get the protection simply by registering an application, like a copyright registration application. The Patent and Trademark Office (PTO) would grant a three-year protection certificate without examination of the merits of the technology advance. If an unauthorized person were to copy the protected article during these three years, that “knock-off artist” would be liable for damages to the registrant. A federal court or the PTO would assess the damages, as the parties elected. The author considers these proposals