可编程工作流程自动控制机床与设备开发与项目(2)

机床电气化系统设计与友好界面的编程开发

Can broadband over powerline carrier (PLC) compete? A techno-economic analysis

PLC面板友好界面与通讯过程分析

Powerline carrier (PLC) communications have been heralded by the FCC as the ―3rd wire‖ to every home, and have matured to the point of field trials and limited deployment. This paper examines the technology from a techno-economic perspective, factoring in regulatory issues and network design (focusing on the United States). Results indicate that PLC does not appear to represent a major disruptive technology, especially from a price-performance perspective. In addition, a baseline stochastic model created for the analysis shows that not only do competition and penetration matter, but locational distribution (i.e., how many consumers can share upstream equipment) is critical in determining PLC's competitiveness.

Design and construction of vacuum control system on EAST

可远程对服务器进行访问的PLC专用控制系统构建与设计 The construction of experimental advanced superconducting tokamak (EAST) was finished at the end of 2006 in Hefei, China. Its vacuum system, an important subsystem, has been commissioned in February 2006. The design and construction of this vacuum control system are described in this paper. The

requirements for remote automation, distributed control and centralized management, high reliability and expansibility have been taken into account in the design.

There are three levels of control in vacuum control system. The bottom level control is performed on the local instruments manually; the medium level control is based on Siemens S7-400 PLC; the top level control is conducted on IPCs with communication through profi_bus network. In addition remote handling and centralized monitoring could be realized by a remote control server.

Specifying and verifying PLC systems with TLA+ : A case study

PLC工作测试系统：案例研究

Abstract

We report on a method for formally specifying and verifying programmable logic controllers (PLCs) in the specification language TLA. The specification framework is generic. It separates the description of the environment from that of the controller itself and its structure is consistent with the scan cycle mechanism used by PLCs. Specifications can be parameterized with the number of replicated components. In our +