PLC 控制系統(tǒng)最初被應(yīng)用于對(duì)離散量的控制,隨著技術(shù)的發(fā)展和實(shí)際工程應(yīng)用的需求,PLC 控制系統(tǒng)也開(kāi)始用于對(duì)連續(xù)變量的控制。結(jié)合實(shí)際工程,對(duì)PID 模塊指令在Allen2Bradley 公司的PLC 產(chǎn)品中的應(yīng)用,進(jìn) 行闡述說(shuō)明。
上傳時(shí)間： 2013-10-18
上傳用戶(hù)：小寶愛(ài)考拉
本次在線座談主要介紹TI的高精度Delta-Sigma A/D轉(zhuǎn)換器的原理及其應(yīng)用，Delta-Sigma A/D轉(zhuǎn)換器在稱(chēng)重儀器中，大量采用比例測(cè)量方法。
標(biāo)簽： Delta-Sigma 高精度 轉(zhuǎn)換器
上傳時(shí)間： 2013-10-17
上傳用戶(hù)：zhqzal1014
Differential Nonlinearity: Ideally, any two adjacent digitalcodes correspond to output analog voltages that are exactlyone LSB apart. Differential non-linearity is a measure of theworst case deviation from the ideal 1 LSB step. For example,a DAC with a 1.5 LSB output change for a 1 LSB digital codechange exhibits 1⁄2 LSB differential non-linearity. Differentialnon-linearity may be expressed in fractional bits or as a percentageof full scale. A differential non-linearity greater than1 LSB will lead to a non-monotonic transfer function in aDAC.Gain Error (Full Scale Error): The difference between theoutput voltage (or current) with full scale input code and theideal voltage (or current) that should exist with a full scale inputcode.Gain Temperature Coefficient (Full Scale TemperatureCoefficient): Change in gain error divided by change in temperature.Usually expressed in parts per million per degreeCelsius (ppm/°C).Integral Nonlinearity (Linearity Error): Worst case deviationfrom the line between the endpoints (zero and full scale).Can be expressed as a percentage of full scale or in fractionof an LSB.LSB (Lease-Significant Bit): In a binary coded system thisis the bit that carries the smallest value or weight. Its value isthe full scale voltage (or current) divided by 2n, where n is theresolution of the converter.Monotonicity: A monotonic function has a slope whose signdoes not change. A monotonic DAC has an output thatchanges in the same direction (or remains constant) for eachincrease in the input code. the converse is true for decreasing codes.
標(biāo)簽： Converters Defini DAC
上傳時(shí)間： 2013-10-30
上傳用戶(hù)：stvnash
ANALOG INPUT BANDWIDTH is a measure of the frequencyat which the reconstructed output fundamental drops3 dB below its low frequency value for a full scale input. Thetest is performed with fIN equal to 100 kHz plus integer multiplesof fCLK. The input frequency at which the output is −3dB relative to the low frequency input signal is the full powerbandwidth.APERTURE JITTER is the variation in aperture delay fromsample to sample. Aperture jitter shows up as input noise.APERTURE DELAY See Sampling Delay.BOTTOM OFFSET is the difference between the input voltagethat just causes the output code to transition to the firstcode and the negative reference voltage. Bottom Offset isdefined as EOB = VZT–VRB, where VZT is the first code transitioninput voltage and VRB is the lower reference voltage.Note that this is different from the normal Zero Scale Error.CONVERSION LATENCY See PIPELINE DELAY.CONVERSION TIME is the time required for a completemeasurement by an analog-to-digital converter. Since theConversion Time does not include acquisition time, multiplexerset up time, or other elements of a complete conversioncycle, the conversion time may be less than theThroughput Time.DC COMMON-MODE ERROR is a specification which appliesto ADCs with differential inputs. It is the change in theoutput code that occurs when the analog voltages on the twoinputs are changed by an equal amount. It is usually expressed in LSBs.
標(biāo)簽： Converter Defi ADC 轉(zhuǎn)換器
上傳時(shí)間： 2013-11-12
上傳用戶(hù)：pans0ul
cv181l-a-20
標(biāo)簽： Specification_V 181 1.0 L-A
上傳時(shí)間： 2013-11-14
上傳用戶(hù)：daijun20803
設(shè)計(jì)了一種以FX3U系列PLC為控制核心的太陽(yáng)能自動(dòng)跟蹤控制系統(tǒng)。該跟蹤控制系統(tǒng)將視日運(yùn)動(dòng)軌跡跟蹤與傳感器跟蹤相結(jié)合，即第一級(jí)采用視日運(yùn)動(dòng)軌跡跟蹤，初步跟蹤太陽(yáng)的運(yùn)行軌跡，第二級(jí)采用傳感器跟蹤校正，并采用雙軸式跟蹤調(diào)整裝置。系統(tǒng)還設(shè)計(jì)了時(shí)間顯示模塊，能夠顯示實(shí)時(shí)時(shí)間，同時(shí)也可以對(duì)時(shí)間進(jìn)行實(shí)時(shí)調(diào)整。
標(biāo)簽： PLC 太陽(yáng)能 跟蹤控制 系統(tǒng)設(shè)計(jì)
上傳時(shí)間： 2013-12-30
上傳用戶(hù)：hz07104032
2012TI杯陜西賽題H題,2012TI杯陜西賽題-A微弱信號(hào)檢測(cè)裝置.
標(biāo)簽： 2012 TI 微弱信號(hào) 檢測(cè)裝置
上傳時(shí)間： 2013-12-17
上傳用戶(hù)：362279997
2011全國(guó)大賽A題開(kāi)關(guān)電源模塊并聯(lián)供電系統(tǒng)
標(biāo)簽： 2011 大賽 開(kāi)關(guān)電源模塊 并聯(lián)供電系統(tǒng)
上傳時(shí)間： 2013-11-10
上傳用戶(hù)：冇尾飛鉈
Avnet Design Service電源實(shí)驗(yàn)室開(kāi)發(fā)出基于MSP430FE427(A) 模塊的電度表解決方案： （1）電壓 (90Vac~264Vac) 與電流 (10Arms) 測(cè)量范圍寬 （2）電度表是一種測(cè)量用電量的設(shè)備 （3）LCD顯示電量 (kWh)、功率 (W)、電壓 (V)、電流 (A)、功率因數(shù)(PF) 與溫度 (oC) 測(cè)量值 （4）264Vac/63Hz與140mW @90Vac/47Hz條件下，無(wú)負(fù)載功耗低于300mW （5）測(cè)量精度高達(dá)2%
上傳時(shí)間： 2013-10-13
上傳用戶(hù)：cjf0304
PMC和PMC-A系列是小型，高性能，恒定電壓，恒定電流的串聯(lián)調(diào)節(jié)器方式的DC電源。采用串聯(lián)調(diào)節(jié)器方式的設(shè)計(jì)，可以在低噪聲輸出等級(jí)的情況下實(shí)現(xiàn)了高穩(wěn)定的輸出。LED數(shù)字儀表在朦朧的環(huán)境中也能清晰易讀，電子開(kāi)關(guān)排除了繼電器的顫動(dòng)，也是這一系列的特征。此外，一部分的PMC-A系列裝備了各種遠(yuǎn)程控制功能，通過(guò)GPIB，可連接電源控制器。
上傳時(shí)間： 2013-10-23
上傳用戶(hù)：GHF
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