基于CANopen协议的多机通讯设计

针对煤矿中多机通讯系统要求远距离、抗干扰性强等特点,介绍了基于CANopen协议的多机通讯设计方法。基于TMS320F2812DSP的变频器平台,采用一主节点和两从节点组成CANopen网路的多机通讯方案。通过主节点与任一从节点的SDO报文和PDO报文的通信以及从节点一致性的实验表明,基于CANopen协议的多机通讯数据传输快速、可靠性高、抗干扰性强。     

串行总线上两种通信模式的融合

介绍了串行总线上的客户机/服务器模式和生产者/消费者模式。根据PLC的多机数据同步的需求,设计了一种将两种模式相融合的通信方式,很好地解决了问题。实验验证了该模式融合的效果。     

Design through making: crafts knowledge as facilitator to collaborative new product development

Collaboration between manufacturers and craft makers is believed by many crafts theorists to offer new originality, insight and specialist expertise to design for production. In practice, however, there exists a discrepancy between this ideal and a reality of unreconcilable cultural and methodological differences. This paper documents and discusses such a collaboration as an example of best practice with implications for managers, educators, designers and craft makers. It identifies a new role for craft makers with the appropriate knowledge and experience to act as bridges within companies, facilitating the adoption of design methodologies appropriate to changing priorities in the manufacturing industries.     

与DSP直接接口的串行ADCDSP101／102及其应用

在某些工业现场和野外工业中，数据采集和数据处理需要分开，此时采用串行通信。在这此串行高速ＡＤＣＤＳＰ１０１／１０２用起来十分方便，因为它们 与标准ＤＳＰ之间可以直接接口。文章主要介绍了ＤＳＰ１０１／１０２的基本操作及其应用实例。     

Power Allocation Strategy for Secret Key Generation Method in Wireless Communications

Secret key generation (SKG) is an emerging technology to secure wireless communication from attackers. Therefore, the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’ uncertainty. However, the physical layer secret key generation (PHY-SKG) depends on two fundamental parameters, i.e., coherence time and power allocation. The coherence time for PHY-SKG is not applicable to secure wireless channels. This is because coherence time is for a certain period of time. Thus, legitimate users generate the secret keys (SKs) with a shorter key length in size. Hence, an attacker can quickly get information about the SKs. Consequently, the attacker can easily get valuable information from authentic users. Therefore, we considered the scheme of power allocation to enhance the secret key generation rate (SKGR) between legitimate users. Hence, we propose an alternative method, i.e., a power allocation, to improve the SKGR. Our results show 72% higher SKGR in bits/sec by increasing power transmission. In addition, the power transmission is based on two important parameters, i.e., epsilon and power loss factor, as given in power transmission equations. We found out that a higher value of epsilon impacts power transmission and subsequently impacts the SKGR. The SKGR is approximately 40.7% greater at 250 from 50 mW at epsilon = 1. The value of SKGR is reduced to 18.5% at 250 mW when epsilonis 0.5. Furthermore, the transmission power is also measured against the different power loss factor values, i.e., 3.5, 3, and 2.5, respectively, at epsilon = 0.5. Hence, it is concluded that the value of epsilon and power loss factor impacts power transmission and, consequently, impacts the SKGR.     

天生桥水力发电总厂通信网及特点

介绍天生桥水力发电总厂以程控交换机为中心，兼备数字微波、电力线载波的通信网及其特点。     

实用化565Mbit／s光发送机

本文介绍实用于565Mbit/s速率上的光发送机,并叙述其工作性能及指标。     

Chopper Modulators Using Current Conveyor Analogue Switches

The new CMOS Cowan, Ring, and Full-AM chopper modulators using current conveyor analogue switches are presented. The proposed chopper modulators use a square wave carrier current for controlling the transfer of a sine wave baseband voltage from nodes Y to nodes X, and the baseband currents from nodes X to nodes Z, of the current conveyors. The proposed chopper modulators are verified by simulating from the layout with a 0.5 μ m/level 49 MOSFET model of AMI obtained through MOSIS. With a supply voltage of ± 1.5 V, the operation range for the baseband voltage is between −300 mV and 300 mV. The operation range for the carrier current, bias currents for CCIIs, is ranged from ten to few hundred microamps. Using the carrier current of 20 μ A, the power consumption is not more than 0.8 mW in the operation range of the baseband voltage.     

碳纤维加固技术在某通信机房改造中的应用

碳纤维加固技术是一种新兴的加固技术，本结合某通信机房加固改造工程，对该加固技术的原理、设计体会和施工方法进行了介绍。     

卫星激光通信粗跟踪系统复合控制策略

针对卫星激光通信粗跟踪系统的跟踪稳定精度指标要求高的特点,建立了基于永磁同步电机直接驱动的粗跟踪系统模型并进行了跟踪稳定误差分析。在采用传统PID控制策略存在跟踪误差较大、动态性能较差等不足的基础上,提出了一种基于粗跟踪系统的改进型前馈复合控制策略。从理论上分析了前馈复合控制策略提高了粗跟踪系统的动态性能,为降低跟踪稳定误差提供了改善方案。地面实验验证结果表明,与传统控制策略相比,改进型复合控制策略极大地降低了系统的动态跟踪误差,动态跟踪误差由606μrad降低至13μrad(1δ)。进一步的在轨实验也验证了改进型复合控制策略的合理性和先进性,总体指标满足了卫星激光通信终端的极高精度要求。本文所提出的控制策略对其他高性能跟踪伺服系统设计也具有较大的借鉴意义。