一种通过SPI接口协议实现DSP与其它设备通信的方法

介绍了SPI通信协议，并着重介绍了TI公司生产的TMS320C5402DSP用于SPI协议通信时的串口配置方法和接口电路设计实例，最后给出了串口McBSP的配置程序。     

对建筑物内通信电缆阻燃特性认识误区的剖析

梳理国内市场对"阻燃"概念的认识,对建筑物内通信电缆阻燃特性的认识误区进行剖析,提出需根据电缆的阻燃分级来辨识电缆的阻燃能力,以选择符合建筑物所要求的阻燃级别的通信电缆。     

交钥匙方案:存在即合理

交钥匙方案(Tum-Key)一直是备受争议的商业模式,它在一定程度上造成了价格竞争,又同时给了一大批厂商在产品设计上更大的自由空间.伴随中国通信行业3G时代的真正开启,厂商之间开始尝试合作,并联合推出"软件+硬件"的交钥匙方案,延续该商业模式在策略上的成功.     

一种叠双菱形天线的改进设计

在对菱形天线结构和工作原理进行分析的基础上,为缩小天线尺寸结构,提高天线的方向和增益特性,设计了一种以2.4 GHz为中心工作频率的带反射板的叠双菱形天线。设计过程中利用VB软件制作了交互式天线计算器,方便天线尺寸参数的计算和优化调整,并使用4NEC软件搭建天线的模型及仿真优化。在天线测试平台上利用PNA3621网络分析仪对制作的天线进行了测试。测量结果表明,在2.35 GHz～2.45 GHz频率范围内,天线方向图较好,与仿真结果较为吻合,天线输入端电压驻波比和回波损耗较为理想。     

A roadmap towards intelligent net zero- and positive-energy buildings

Buildings nowadays are increasingly expected to meet higher and more complex performance requirements: they should be sustainable; use zero-net energy; foster a healthy and comfortable environment for the occupants; be grid-friendly, yet economical to build and maintain. The essential ingredients for the successful development and operation of net zero- and positive-energy buildings (NZEB/PEB) are: thermal simulation models, that are accurate representations of the building and its subsystems; sensors, actuators, and user interfaces to facilitate communication between the physical and simulation layers; and finally, integrated control and optimization tools of sufficient generality that using the sensor inputs and the thermal models can take intelligent decisions, in almost real-time, regarding the operation of the building and its subsystems. To this end the aim of the present paper is to present a review on the technological developments in each of the essential ingredients that may support the future integration of successful NZEB/PEB, i.e. accurate simulation models, sensors and actuators and last but not least the building optimization and control. The integration of the user is an integral part in the dynamic behavior of the system, and this role has to be taken into account. Future prospects and research trends are discussed.     

PDM使新产品开发设计过程一体化

介绍了日本NEC移动通信分公司采用PDM系统,帮助行政管理部门与加工车间共享CAD数据.以较低的成本、更快的速度、更少的误差实现新产品的在线设计和开发.     

本钢2300mm热轧AWC控制简析

全面、系统地对本钢2300mm带钢热连轧生产工艺过程中,带钢宽度控制的起因以及影响最终产品宽度的要素进行了介绍,并对当前使用的自动宽度控制系统的设计进行了介绍,给出了控制系统原理图、可实现的程序框图及控制策略应用。结果表明,该方法能有效地控制产品宽度。     

Parasitic effects of the metallic towers on the characteristics of the broadcast antennas

In this article, we use a tool NEC (Numerical Electromagnetic Code) to model antenna on top of a tower structure. Simulation results for the parasitic effect of the tower on characteristics of broadcast DVB‐T (Digital Video Broadcasting Terrestrial) antenna such as input impedance, return loss, gain, front‐to‐back ratio and radiation patterns are reported. In addition, the effect of a nearby tower on antenna characteristics is studied. A 3D tower and broadband antenna in the UHF (470‐862) MHz band are constructed. The antenna works for both digital and analog TV with return loss (RL) ≥ 10 dB, fractional bandwidth of 87% and gain of 12.3 dBi at center frequency. The effective radiated power is calculated by mounting the antenna at each face of the tower to give a satisfactory coverage to a region around the antenna.     

基于NEC8253实现步进电机无级调速系统的设计

介绍了一种以89C 51单片机为主控芯片,选用可编程定时/计数器NEC 8253控制步进电机的脉冲频率,实现其无级调速,从而控制悬挂物体运动的设计;给出了系统主要的硬件电路、软件设计。实验结果表明,该方案具有很好的灵活性。