Abstract: As industrial control systems (ICSs) have become increasingly connected and use more off-the-shelfcomponents, new vulnerabilities to cyber attacks have emerged. This tutorial looks at three types of ICSs:programmable logic controllers (PLCs), supervisory control and data acquisition (SCADA) systems, anddistributed control systems (DCSs), and then discusses security issues and remedies. This document alsoexplains the benefits and limitations of two cryptographic solutions (digital signatures and encryption) andelaborates on the reasons for using security ICs in an ICS to support cryptography.
標(biāo)簽： 工業(yè)系統(tǒng) 安全問題
上傳時間： 2013-10-09
上傳用戶：woshinimiaoye
Modern electronic systems solve so many difficult problems that they often seem like magic. Nonetheless, these systems all have thesame basic limitation: they need a source of electrical power! Most of the time this is a straightforward challenge for the electronicdesigner, because there are many power-delivery solutions. Yet sometimes a device has no direct power source, and running wiresor replacing batteries is impractical. Even when long-life batteries are usable, they eventually need to be replaced, which requires aservice call.
標(biāo)簽： 能量收集
上傳時間： 2015-01-03
上傳用戶：zukfu
The high defi nition multimedia interface (HDMI) is fastbecoming the de facto standard for passing digitalaudio and video data in home entertainment systems.This standard includes an I2C type bus called a displaydata channel (DDC) that is used to pass extended digitalinterface data (EDID) from the sinkdevice (such as adigital TV) to the source device (such as a digital A/Vreceiver). EDID includes vital information on the digitaldata formats that the sink device can accept. The HDMIspecifi cation requires that devices have less than 50pFof input capacitance on their DDC bus lines, which canbe very diffi cult to meet. The LTC®4300A’s capacitancebuffering feature allows devices to pass the HDMI DDCinput capacitance compliance test with ease.
上傳時間： 2013-11-21
上傳用戶：tian126vip
ACPR (adjacent channel power ratio), AltCPR (alternatechannel power ratio), and noise are important performancemetrics for digital communication systems thatuse, for example, WCDMA (wideband code division multipleaccess) modulation. ACPR and AltCPR are bothmeasures of spectral regrowth. The power in the WCDMAcarrier is measured using a 5MHz measurement bandwidth;see Figure 1. In the case of ACPR, the total powerin a 3.84MHz bandwidth centered at 5MHz (the carrierspacing) away from the center of the outermost carrier ismeasured and compared to the carrier power. The resultis expressed in dBc. For AltCPR, the procedure is thesame, except we center the measurement 10MHz awayfrom the center of the outermost carrier.
標(biāo)簽： AltCPR WCDMA 5528 ACPR
上傳時間： 2013-11-02
上傳用戶：maricle
Frequently, voltage reference stability and noise defi nemeasurement limits in instrumentation systems. In particular,reference noise often sets stable resolution limits.Reference voltages have decreased with the continuingdrop in system power supply voltages, making referencenoise increasingly important. The compressed signalprocessing range mandates a commensurate reductionin reference noise to maintain resolution. Noise ultimatelytranslates into quantization uncertainty in A to D converters,introducing jitter in applications such as scales, inertialnavigation systems, infrared thermography, DVMs andmedical imaging apparatus. A new low voltage reference,the LTC6655, has only 0.3ppm (775nV) noise at 2.5VOUT.Figure 1 lists salient specifi cations in tabular form. Accuracyand temperature coeffi cient are characteristic ofhigh grade, low voltage references. 0.1Hz to 10Hz noise,particularly noteworthy, is unequalled by any low voltageelectronic reference.
標(biāo)簽： 低噪聲 電壓基準(zhǔn) 噪聲測量
上傳時間： 2013-10-30
上傳用戶：wxhwjf
Automobiles, aircraft, marine vehicles, uninterruptiblepower supplies and telecom hardware represent areasutilizing series connected battery stacks. These stacksof individual cells may contain many units, reaching potentialsof hundreds of volts. In such systems it is oftendesirable to accurately determine each individual cell’svoltage. Obtaining this information in the presence of thehigh “common mode” voltage generated by the batterystack is more diffi cult than might be supposed.
上傳時間： 2013-10-24
上傳用戶：kang1923
This application note discusses a variety of approaches for interfacing analog signals to 5V powered systems. Synthesizing a "rail-to-rail" op amp and scaling techniques for A/D converters are covered. A voltage-to-frequency converter, applicable where high resolution is required, is also presented.
標(biāo)簽： 微處理器 系統(tǒng)接口
上傳時間： 2013-10-12
上傳用戶：181992417
A collection of interface applications between various microprocessors/ controllers and the LTC1090 family of data acquisition systems. The note is divided into sections specific to each interface.
上傳時間： 2013-11-08
上傳用戶：sssnaxie
ECHNICAL COMMITTEE No. 65: INDUSTRIAL-PROCESS MEASUREMENT AND CONTROL WORKING GROUP 6 VOTING DRAFT - PUBLICLY AVAILABLE SPECIFICATION - FUNCTION BLOCKS FOR INDUSTRIAL-PROCESS MEASUREMENT AND CONTROL SYSTEMS
標(biāo)簽： INDUSTRIAL-PROCESS MEASUREMENT COMMITTEE ECHNICAL
上傳時間： 2014-10-28
上傳用戶：源弋弋
ECHNICAL COMMITTEE No. 65: INDUSTRIAL-PROCESS MEASUREMENT AND CONTROL WORKING GROUP 6 VOTING DRAFT - PUBLICLY AVAILABLE SPECIFICATION - FUNCTION BLOCKS FOR INDUSTRIAL-PROCESS MEASUREMENT AND CONTROL SYSTEMS
標(biāo)簽： INDUSTRIAL-PROCESS MEASUREMENT COMMITTEE ECHNICAL
上傳時間： 2015-02-11
上傳用戶：baiom
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